List of The Rookie episodes

Nine months after witnessing (and foiling) a bank robbery in his small town of Foxburg, Pennsylvania, John Nolan, a 45 year old divorcé, packs up his entire life to move to Los Angeles and becomes a cop. His assignment to the force, particularly the Mid-Wilshire Division of the LAPD is met with skepticism from his fellow officers, particularly his watch commander, Sergeant Wade Grey, and his training officer Talia Bishop. Nolan's first few days on the job are marked by a domestic dispute that quickly escalates out of hand (during which Nolan witnesses his first death), an unbalanced father who leaves his child in a locked car on a hot day, and an escaped felon who quickly tests Nolan in ways he never expected. Also joining Nolan as rookie officers are Jackson West, son of a high-ranking LAPD officer and eager to live up to the family legacy, and Lucy Chen, who became a cop against the wishes of her therapist parents and is carrying on a secret affair with Nolan despite the risk it poses to her career. Sergeant Grey tells Nolan that he will do everything in his power to discourage him from continuing to serve, as he fears that Nolan's inexperience and age will endanger the lives of his officers. Nolan tells Grey that he believes being a cop might be his calling. Grey responds that if that is true, nothing Grey puts Nolan through will deter him.

Nolan prevents a woman from killing herself after she tries to jump off of the Hollywood Sign after her wedding does not go as planned. Jackson is questioned as to why he didn't fire his weapon in a previous call, but his TO Angela Lopez covers for him. She then forces him to handle the arrest of a man on PCP, which he pulls off. Nolan and Talia arrest an addict for possession of drugs, but then learn that she fatally stabbed a teenager in an argument. Lucy is stuck with a lazy new training officer while her original TO Tim Bradford recovers from a gunshot wound, and winds up arresting a man for shoplifting. Nolan continues to face difficulties in navigating between his civilian instincts and how they affect his actions as a cop. Jackson is able to subdue a suspect without assistance. Nolan is assigned a rusty old car as punishment for damaging his vehicle. A kidnapping victim is rescued, and Nolan and Talia obtain a lead on the kidnapper. While apprehending him, Talia stops Nolan from beating the suspect in a rage. Captain Zoe Andersen thanks him for his success, but reminds him that it is not his job to punish criminals. Lucy finds out that Tim, who's recovering from being shot in the previous episode, intentionally got her assigned to a poor officer to test her commitment. Talia is able to get Nolan a new vehicle, which he nearly crashes on his first drive.

Nolan and Talia chase a group of thieves and Nolan loses a bag of stolen money when a street performer runs off with it. The precinct learns that the thieves are part of a gang who have pulled off a string of heists and they begin searching for the remaining gang members. Meanwhile, Lucy helps Tim as he readjusts to being back on duty while also trying to help his drug addicted wife Isabel, who reveals to Lucy she was once a narcotics cop. Elsewhere, an arrest of a former college athlete causes Jackson and Lopez to talk about alternative careers to police work since Lopez still doubts Jackson's ability to handle the job.

Sgt. Grey tests the rookies by assigning them new TOs, partnering Nolan with Lopez, Jackson with Tim, and Lucy with Talia. He tasks the rookies with gaining insight into their new TOs. Lopez takes Nolan to court and Nolan ends up chasing an escaped prisoner, leading to a potentially career-making bust for the pair. Tim, however, learns about Jackson's struggles when he freezes during a shootout and enraged, confronts Lopez over it. Tim later takes Jackson to meet an agoraphobe who gives Jackson advice on facing his fears. Meanwhile, Lucy defends her relationship with Nolan to Talia during their patrol, prompting Nolan and Lucy to have a talk about their relationship.

Nolan struggles to deal with his breakup with Lucy just as the TOs start an annual competition to see who can get the most arrests in a single shift. Tim plays to win, even bribing a dispatcher to get the best calls, which worries Lucy. Meanwhile, Jackson dives headfirst into the competition to prove himself while Nolan and Talia, who is refusing to play, find themselves dealing with a mob-connected banker.

Upon learning that his former academy instructor, Jeremy Hawke, has fallen on hard times, Nolan offers to help him out. Jeremy politely declines but, the next morning, Lopez and Jackson answer a call from Jeremy's estranged wife. She claims Jeremy has become unstable and dangerous. Nolan and Talia get involved in the pursuit of Jeremy, which quickly escalates. Then, they discover Jeremy has his son with him, who is willingly participating with his father's fugitive activities. Meanwhile, Jackson and Lopez deal with a shooting victim and his father, both of whom they suspect aren't telling them the whole truth and Tim tries to teach Lucy to anticipate the behavior of criminals.

Nolan and Talia are assigned Hollywood director Rupert Payne, of whom Nolan is a fan, for a ride along to research his new film. Despite orders to keep him away from any dangerous situations, Rupert observes Nolan and Talia deescalate a situation involving a mentally impaired young man from a troubled neighborhood, which leads to a dangerous situation when Rupert tries to help the young man's family. Meanwhile, Jackson informs Lopez that she is being considered for detective, which prompts Lopez to attempt leveraging smaller criminals into giving up a major player, which ultimately backfires. Elsewhere, Tim's wife Isabel is arrested in a drug bust, forcing Tim to choose, once and for all, between his devotion to Isabel and his duty as a cop.

While in pursuit of a robber, Nolan fatally shoots him in self defense. The episode centers on the processing of this event. Tim's wife Isabel is returning to be a CI. While trying to get evidence against a major drug trafficker, the connection to her wire is lost and Talia and Tim find the camera and blood upon searching the apartment. Isabel seems to have been taken by the drug traffickers. Lucy gives Nolan a ride home from the precinct and they sleep together. While Lucy is in the shower, the brother of the robber attacks Nolan. The episode ends with Nolan's attacker holding a gun on Nolan and a shot fired off camera.

Nolan manages to fight off his attacker, throwing him through the window and calling for backup. Meanwhile, Tim, Lopez, and Talia find Isabel. She has been shot in the head but will survive. Nolan lies repeatedly to Commander Percy West about his affair with Lucy. Nolan is assigned to desk duty during the investigation of his attack. Tim, Lucy, Jackson, Lopez, Talia, and Detectives Wolfe and Vestri go to an apartment building to find Vance, the drug dealer who shot Isabel and left her for dead. Things go sideways and they end up in a shootout with Vance and his men, resulting in Vestri being killed and Wolfe seriously wounded. Lucy helps deliver Vance's girlfriend's baby while Jackson is able to turn off the power to a frequency jammer, so Talia can call for backup. Vance and his men break into the apartment and fight with Tim and Lucy. The other officers, including Nolan, Percy West, and the SWAT team arrive and Vance and his men are arrested. Lucy tells Nolan not to tell the truth about what really happened the previous night. Nolan reports to Andersen and Percy and the latter informs him that he has been cleared of all charges and can return to the police force immediately.

Henry Nolan comes to visit his dad, who is surprised to learn that Jackson and Lucy already know Henry through social media. At morning roll call, Andersen announces she will ride along with Lucy, while Grey will partner with Nolan, and Tim and Talia will partner with each other. Grey's daughter Dominique also shows up unexpectedly for an internship. Henry and Dominique bond over their concern over their dads' work, and Tim and Talia clash over procedure, as each is used to being the boss of their rookie. The episode ends with Nolan and his son talking about Nolan's job. Henry worries about the danger he is in. Nolan agrees to text his son at the end of each day with a code word to let him know he is okay.

The officers are forced to come in to work on their day off, as the Vice President has made an unexpected visit to Los Angeles. Nolan and Talia stop a man who was a threat to the Vice President after they find a flare gun in his underwear. Lucy gets pricked by a used needle while trying to break up a fight between two homeless women and is forced to go to the hospital. Tim tries to comfort her as she could have various diseases as a result of getting injected. Meanwhile, Lopez and Jackson try to break up protestors and tell people who have obscene banners to take them down. Nolan and Talia engage in a shootout with several robbery suspects. When Lopez and Jackson defy Agent Danvers' orders and decide to go help Bishop and Nolan, Grey defends them, saying it was the right thing to do. During the episode, Jackson has trouble focusing on the job and nearly loses his cool with a man who left his elderly mother in hand restraints. At the end of the episode, Jackson waits with Lucy as she gets good news about her diagnosis. Jackson tells Lucy about his family problems and Nolan sells his house in Pennsylvania after having a dilemma about what to do with it.

The evening before Valentine's Day, the rookies are on a night out in the same location as Grey and his wife Luna. When the rookies have to leave, Nolan gets in trouble with a man harassing a woman at the bar, ruining Grey's evening. On Valentine's Day, Tim takes a day off to meet up with Isabel, who is in rehab. They end up breaking off their relationship, with Tim telling Isabel that she'll never move past who she was as an addict if they remain together. Nolan and Talia arrive at a car crash where Nolan saves the driver's life. The driver lost her husband a year ago and tries everything to get together with Nolan, even cozying up to Ben to get close to Nolan. Lopez and Jackson interrogate an alleged assault victim who claims to suffer from dementia, but turns out to be a dangerous criminal. Jackson hits it off with a male nurse. Lopez searches her boyfriend Wesley Evers' smartphone, assuming he cheats on her, but in the end, it turns out to be different than what she had thought. Nolan arranges a party for his first Valentine's Day in a long time without company and is surprised when Talia attends.

Talia and Nolan respond to a car accident and find the victim has been stabbed, but he escapes from the ambulance and flees the scene. To their surprise, he turns up at the station, stating his name is Ortiz and that he is an undercover officer with the LAPD investigating a drug cartel, which plans to transfer one million dollars that night. The LAPD raids the home before the transfer, and the rookies are put in charge of the scene until the money counters arrive. The counters finish, and $250,000 is missing. The rookies are interrogated, polygraphed and cleared, but still suspended. Lucy is surrounded and attacked by members of the cartel and forced to flee. Nolan and Jackson are on the phone with Lucy during the attack, and notify the LAPD before rushing to her aid. Meanwhile, the cartel boss and his men catch up to Lucy and demand to know where she hid the missing money – Lucy realizes that the cartel boss must have hidden the money himself, recognizing his boots as belonging to the same man she saw leaving the house before the raid with a large duffel bag. The boss shoots his men, but after a scuffle is subdued by Lucy while Captain Andersen visits Ortiz and informs him he's being arrested as he was the one involved in the scheme all along. Nolan agrees to pay Ben what he can for his apartment on a monthly basis to ensure that he is not accepting goods or services for free, which would imperil his status as a police officer.

The rookies undergo Plain Clothes Day, where their training officers ride along out of uniform and do not assist in any capacity. Jackson is eager to break his father's records but gets stuck working behind a desk after their patrol car breaks down before departing. He eventually overcomes his frustrations with desk duties, and assist the widow of murder victim Richard Ocheda, with returning a cheap watch from the crime scene. Lucy is confident that she can handle herself but Tim is intent to rattle her as much as possible. Her first mistake becomes not to impound a van used by a stalker who targeted women, which Tim has already cleared after noticing her mistake. After responding to a noise complaint about a dog, the dog owner files a complaint about Lucy for threatening him. Lucy later redeems herself after suspecting foul play at the owner's house, where it is revealed that he murdered the woman who filed the noise complaint. Nolan, meanwhile, works hard to prove himself as he announces his intent to make detective within five years. He lets one suspect go after trying to arrest a second one, but later spots the first suspect along the street. While stopped at a hotel, Nolan discovers a warrant for the owner of parked vehicle, but after raiding the hotel room the owner is believed to be staying in, it's revealed that the vehicle was sold to a woman and her child. He also dismissed a distressed woman with questions about credit card tracking, only to later find her to be a kidnapping victim of her abusive and violent husband. Talia decides to assist Nolan, while he distracts the husband, eventually arresting him and freeing the woman.

A prisoner transport crashes while on the road and several violent criminals are on the loose in suburban Los Angeles. After tending the wounds of wounded deputy, Nolan is attacked by one of the prisoners, but quickly subdues him before Lopez and Jackson arrive. Tim and Lucy capture another prisoner on the loose in a neighborhood, and also clash with a local militia. Jackson and Lopez capture Oscar Hutchison in a parking garage. At the station, Oscar makes subtle hints that Jackson's father Percy was corrupt earlier in his career, which Jackson subsequently dismisses. Nolan and Talia inspect vehicles going into a neighborhood, and Nolan discovers one vehicle where the driver seems distressed. One of the prisoners is revealed to be hiding in the vehicle's trunk holding the driver’s daughter hostage. Nolan chooses to let the driver go and, when he arrives home and pulls into the garage, the police are waiting and prisoner is arrested. Tim and Lucy, along with Tim's informant Deacon, find the last prisoner, Marcos Gibson, and protects him from angry members of the 5–4 gang, until backup arrives. Nolan single handedly tackles a hostage situation with Caleb Jost, the second last prisoner, bales on advice from Jessica Russo. Tim also decides to start taking his sergeant exams.

Internal Affairs is conducting random integrity tests at the precinct to ensure officers are following procedure. During an arrest of Nolan's, the shoulder strap on an unruly lady's dress accidentally breaks. Assuming she's with IA when she asks Nolan for his badge number, he complies. Later that evening, a gunman with an assault rifle attempts to kill Nolan, who learns a hit has been put on his life by the unruly lady's boyfriend Cole Midas, whose father Leonard is the leader of a violent white supremacist gang, the Southern Front. After some soul-searching, Nolan returns to work the next morning and is partnered with Captain Andersen. Officers seize millions of the gang's assets, and Sergeant Grey visits the imprisoned Leonard to call off the hit on Nolan. But while on patrol, Nolan and Andersen are captured by Cole when responding to a false home burglary call he orchestrated. Cole later kicks a handcuffed and seated Andersen into the backyard pool, but she's able to free herself and kills two gang members, saving Nolan. However, during the shootout, a fleeing Cole fatally shoots Andersen through her neck with Nolan being left there with Andersen's corpse as Tim, Talia, Lucy, Lopez, Jackson, and the other LAPD members arrive and discover what's happened. The officers salute Andersen. Later, Grey revisits Leonard and demands he hand over his son. At the end, an ambush is set, and Cole is arrested by Nolan.

Jessica arranges for Nolan, accompanied by Tim, to be put on a protective detail for a former border patrol guard who became a human trafficker. Grey struggles with the orders issued by the new captain, while Jackson deals with relationship issues. Lucy and Talia save a young man from a brutal exorcism performed by his mother, but Lucy confronts her father, a therapist whose arm was broken by a patient. She is forced to arrest him, causing disappointment from her father. However, she redeems herself by having the patient transferred to the help he needs. An earthquake then rocks the city, leaving Grey to try to coordinate the city's response while Nolan and Tim are attacked at the safehouse. It turns out that their human trafficker had a GPS tracker on him, which led the cartel to the safehouse and subsequently the beach which Nolan and Tim brought him to.

Nolan comes under fire after a man claims Nolan used excessive force and inflicted an injury, and he is assigned to the youngest lawyer, Simon Parks Jr. (Robbie Kay), available for his case. A detective is also investigated and arrested by Internal Affairs. This causes three criminals to be released from prison early. Lopez and Jackson take the case of Samantha Bennett, while Tim and Lucy check in on Max Kegel, and Nolan and Talia investigate Terry Wright. Terry recognizes Talia, as his associate Dylan Scott is Talia's former foster brother. Dylan and Terry later kidnap Talia after she tries to arrest them, leading to Nolan leaving his court hearing early. Dylan kills Terry after Terry attempts to kill Talia, and Talia admits to Grey that she lied about Dylan being her foster brother when applying to the academy. Jackson also confronts his father Percy about the latter being a dirty cop, which strains their relationship when Jackson learns that is not true.

A few days before the rookies' final exam, Tim and Lopez reveal that Lucy and Jackson still have seven and four types of crime to witness, respectively, and must do so in the next 48 hours. Since Nolan has no outstanding crimes, he is assigned to desk duty while Talia goes before Internal Affairs, but he asks to work with Wolfe instead. While on the streets, Lucy and Jackson come across Ben, who was the latest victim of a car theft ring. Nolan ends up helping to catch the thieves, and tries to plead Talia's case in front of Internal Affairs. The episode ends with Talia being offered an opportunity to become a mole for IA, and Nolan telling Ben both about the trauma he suffered after the bank robbery seen in the Pilot episode, and how he got over it.

On the day of an important rookie exam, an isolated terrorist cell plot to use a weaponized virus threatens to derail the rookies' advancement as well as put strain on Nolan's personal relationships. While responding to the threat, Tim may be infected with the virus, while Jessica shoots a surrendering terrorist, straining her relationship with Nolan. Meanwhile, Lopez and Jackson also save several people on a bus by apprehending a second terrorist, which allows Jackson to make amends with his father regarding their previous argument. Once the virus has been contained, Tim is given a dose of the experimental vaccine, but then collapses after leaving the house.

As Tim is rushed to the hospital, a third terrorist from the previous attack ambushes the police; Nolan and Tim, who had only suffered an allergic reaction to medication he was given, then take her out. Two weeks later, it is revealed that Talia resigned from the LAPD and has joined the ATF as a Special Agent while Nolan has moved into a new home, and the rookies learn the scores of their midterm exams, Nolan getting the highest score of 97, Lucy 91 and Jackson 81. They all pass, but Jackson is upset with his score. The team learns of a plan involving fake police officers after Nolan and Grey witness a robbery at a police uniform store. They later find one of the robbers dead after his partners killed him and set his body on fire. Lucy witnesses a fake police officer stealing a radio, but is unable to apprehend him before he escapes. Later, a clerk at the criminal court house is abducted, and Nolan helps to save her life after subduing the fake officer that Lucy had seen earlier. Tim, Lucy, Lopez, and Jackson also arrest the other fake cops following a shootout. Jackson is demoted by Grey, as Grey is disappointed in Jackson's speech that he had given to a group of cadets earlier. As a result, he cannot wear short sleeves until Grey can trust him again.

Jackson arrests his landlord for dealing drugs, but he is forced to move as his building has been declared a "house of ill repute". Nolan is assigned as partner to new detective Nick Armstrong and their investigation into a recent murder leads to an unexpected reunion with Nolan's old love interest Grace. Lucy is also still upset at Tim because he will not allow her to wear short sleeves even though she passed the midterm exam. Meanwhile, the father of the murder victim kills one of the men who murdered his son, and nearly kills the other suspect as well by placing him in a concrete mold, before Nolan and Armstrong manage to save him. However, the father commits suicide by hanging himself from a metal cable in a warehouse despite Nolan's attempts to persuade him not to. Jackson attempts to move into Smitty's trailer park as he doesn't have a place to live. However, Lucy learns of his predicament, and she allows him to move into her apartment.

Nolan tries to navigate his relationship with Jessica and he builds a rapport with Grace while investigating a criminal case involving a homeland security agent with Lopez. Jackson is assigned to Officer Smitty for the day and he struggles to deal with the laid-back and lazy Smitty. Later, a criminal that Jackson is patting down escapes and the criminal drops his gun in a nearby yard. A young boy, believing that the gun is a toy, picks it up and accidentally shoots his mother fatally, infuriating Jackson. They are later able to capture the criminal following a search after learning that the gun was used in another murder as well. Lucy also sets up Tim on a date with Rachel Hall, a social services agent and a friend of Lucy's from college, as part of a bet. Lucy later discovers that Tim and Rachel are now dating, meaning that she has won the bet and can go back to wearing short sleeves.

Nolan gets introduced to a new training officer, Nyla Harper, a former undercover detective. He is confused by her extreme police tactics, notably overseeing minor offenses. They pull over a car with no plates and all four occupants flee, with one falling from a roof top. Harper puts forward her body cam, showing he jumped himself and she didn't push him. While on patrol, they encounter Ross Teagan, a known drug dealer from Harper's past. An operation is commenced to set up Ross, but another suspect, Osito, is spotted leaving the scene by Nolan and when she later tells him she doesn't answer to him, Nolan agrees but informs her that if she's committed to making this an antagonistic relationship, then he won't roll over and take it. Together with Tim and Lucy, Nolan and Harper descend on Osito's location, leading to his arrest. Grey also has Harper apologize to Nolan for her treatment of him, which he accepts. Tim struggles to find a birthday gift for Rachel, and reluctantly accepts help from Lucy. Jackson and Lopez apprehend two boys who harassed a homeless woman, Alice Sheldon, whom turns out to be responsible for a hit and run ten years ago that left the victim paralyzed and eventually caused Alice to suffer a breakdown and become homeless. They track down her victim based on a photo she left, who is identified as Karin Arnoux. Despite initially being against Lopez's defence of Alice, Karin later decides to speak to the DA on Alice's behalf.

Lucy's mother comes to stay with her after having an argument with Lucy's father, frustrating Lucy. Nolan deals with surprising news that his son Henry is now engaged with his girlfriend, Abigail. The rookies also recruit their first confidential informants. Nolan's first informant is a drug dealer, Bianca, who despite surviving an operation, first attempts to escape before it starts, and then overdoses afterwards. Armstrong helps Nolan by giving him a list of informant candidates. He also does a background check on Henry's girlfriend, which makes Nolan uncertain if he should read it or not. Nolan and Harper try their luck with a forger, whom they easily flip. While awaiting a deal to go down at Whiteman Airfield, the buyers turn out to be women on the run from a cartel. The cartel's right hand man arrives, but escapes just as reinforcements arrive. Tim and Lucy deal with a young woman who is selling her stepmother's belongings to a pawn shop out of revenge for her cruel treatment of her. Despite Lucy urging her to change her ways, the girl ends up buying a gun and threatening her stepmother before firing shots at her expensive bags. Lopez and Jackson try to flip a known FBI informant, who they later discover lied about his ex-wife sleeping with a known car dealer. They use this to their advantage to flip him completely the second time, leaving the FBI handler furious. However, this impresses Grey, who allows Jackson to finally wear short sleeves. Grace reads Abigail's background check, revealing that Abigail committed arson in the past, and Nolan brings it up to Henry and her. Abigail explains the truth about her arson, after which Nolan apologizes to her.

The officers deal with an impending missile attack and also deal with their own disasters. Nolan attends a probationary court hearing, and he, Jessica, and Wesley help calm people down during the threat. They all hide in a fallout shelter, and Nolan and Jessica help subdue two prisoners that attempt to escape. Harper picks up her daughter from school, and has Rachel watch her at the station. Tim and Lucy also help a store owner deal with looters while Lopez and Jackson help save several people who are preparing to jump off of a building. Harper's ex-husband Donovan is furious at her for picking up their daughter and wants her arrested, but Nolan helps convince him that she has changed for the better. Wesley is also stabbed by one of the prisoners, Oscar Hutchinson, during the escape attempt and is hospitalized, but he survives his injuries.

The relationship between Nolan and Jessica gets a lot more complicated after she delivers news that she might be pregnant. Nolan also assists Grace at the hospital at a meeting for expectant mothers, where he helps to subdue the unruly boyfriend of one of the women. Lopez is on temporary leave from the force following Wesley's stabbing, and she takes a job in private security escorting a high profile businessman. Officers Tim and Jackson also help out the Watts Rams as volunteer coaches, and they help rescue the mother of one of the team's star players from several armed kidnappers. Lucy and Harper are also assigned to one another, and have several disagreements before they work together to subdue a serial bomber. Nolan and Jessica break up after Jessica asks him to have kids as Nolan isn't ready to have more kids of his own.

Nolan kicks off his birthday by babysitting a crime scene at a law office. He meets Ellroy Basso, a professional cleaner, and they have to evade two criminals when they return to the scene looking for a hidden stash of money. Meanwhile, Tim is involved in an accident when he rear-ends a woman while on patrol. Jackson is also exposed to a substance during a traffic stop and begins to act like he is on drugs. Sgt. Grey also rides patrol with Officer Harper after she requests an early annual evaluation to better her chances of getting custody of her daughter, and Grey observes her compassion in dealing with a near-drunk driver who was depressed after a cancer diagnosis. In the end, it is revealed the boyfriend of the woman Tim hit is intentionally scamming people to earn money by disconnecting the brake lights on the woman's car. Tim and Lucy also thwart a potential murder that the woman's boyfriend is trying to commit. Jackson is evaluated at the hospital but his exposure to the substance is not as serious as initially feared, allowing both Tim and Jackson to receive a special award from the deputy chief.

Nolan's trust is tested when he tries to help the previous owner of his home reconnect with his family. Nolan later has to subdue and arrest him when the other man breaks into the house in the middle of the night. Meanwhile, Officer Harper has finally earned an overnight visit with her daughter that is put into jeopardy when her past undercover life resurfaces again. Nolan also has to go undercover in order to save Harper's life. Tim and Lucy deal with a murder when a lost dog is found covered with blood, resulting in a disturbing case where a woman was killed by her own son because she broke up with her boyfriend. Wesley is brought in as the kid's lawyer, but struggles with PTSD from when he was stabbed after the boy brings up the knife. Lopez and Jackson assist the stars of a police drama by showing them proper LAPD procedure after running into the lead actor during an arrest, with Jackson hitting it off with the actor while Lopez assists his co-star in dealing with a stalker, learning that the stalker is one of the production crew who shoots Jackson before she is subdued.

The department is tasked with assisting convicted serial killer Rosalind Dyer (Annie Wersching) to find the remains of 3 of her victims in exchange for commuting her death sentence to life in prison. While on the way to her gravesites, the team is forced to stop a man from killing her, and they discover new bodies in Rosalind's gravesites. Nolan talks to Rosalind about the possibility of there being a third victim, as two bodies were found along with Rosalind's original kills, having been killed by a different serial killer. Rosalind refuses to help them, and the team is forced to find the new victim on their own. Nolan and Harper manage to find the third victim alive but the killer manages to escape after attempting to drown Nolan in a storm drain. The episode ends with Lucy being drugged and forced into the back of a car by her date at a bar.

Lucy awakes after being drugged by her date, tattooed by him with her "day of death". The station works to find Lucy after they all realize they haven't seen her in 13 hours. It is revealed that her date, Caleb Wright, is the protégé of Rosalind Dyer. Caleb orders Lucy to get in a barrel at gunpoint, which he proceeds to bury in the middle of the desert, but not before she drops a ring for the officers to find. As the station works to find her, Caleb proceeds to kidnap Armstrong and take him to a house that belonged to Rosalind's uncle. Nolan and Harper proceed to track Caleb to the house, where Harper fatally shoots Caleb to save Armstrong. With Caleb dead, the officers spread out and search for loose dirt to find Lucy, with Tim finding and performing CPR on her, saving her life. Meanwhile, Lopez and Wesley discuss his mental health after she found him unconscious after mixing his pills with alcohol. Wesley decides to go to work after seeing what Lucy went through and acknowledges that he can seek help. Nolan visits Rosalind in prison, revealing that they found the locations where she buried her victims, meaning there will be no more deals. Rosalind tells him that she has one more secret, which is about Armstrong. Nolan tells her that he doesn't care about that but Rosalind replies that she knows he'll be back.

Nolan takes his son's fiancé Abigail on a ride-along with Tim after she reveals she wants to be a police officer. Tim offers to put in a word for her at the police academy, but tells Nolan that she won't be able to become a cop due to her criminal record. Harper asks Tim to switch rookies for the week, where she will ride with a recovering Lucy. Lucy struggles to trust her judgment again, so Harper and Lopez take her to speed dating to try to regain her judgment. Lucy gets triggered and snaps when one of the men at the event pulls a loose thread on her sweater, throwing him to the ground. Lucy says that Harper will never understand what she went through, where Harper later reveals that she was raped by her UC handler and implies that she sent him to early retirement, throwing him down some stairs.

Nolan learns of the news that his father has recently died, and is sent his inheritance by a lawyer, which includes an old car. The rookies and their training officers are put through follow up day, where they're assigned dormant cases. Nolan and Harper investigate a robbery of lottery tickets which also left the wife of the store owner dead. Their leads point then to a strip club, where a pole dancer, Chastity, recognises the suspect they're looking for, Tucker Novak, on CCTV footage. Tucker points them to Colt Henry after they arrest him. They find him at the train station, arriving from Sacramento. Colt attempts to flee and holds an infant child at gunpoint before Nolan manages to negotiate with him into giving up. Jackson and Lopez investigate the theft of a statue, which they find lying over the alleged thief when they go door to door through the neighbourhood. Back at the station, Lopez encounters Wesley's mother who has been arrested for possessing an unlicensed gun. Wesley takes part in the case, and learns that his mother got the gun from Christian Roberts, who has a record of armed robberies. Lopez and Jackson track down Christian and arrest him after he attempts to escape. Tim and Lucy investigate a case of money laundering involving Nevin Cooper, who has gone through rehab and working at a local bakery, but is still in debt to his former gang. After encountering Nevin seemingly being threatened by the gang, Tim later attempts negotiate with their leader, Marquel, to let Nevin be, but he refuses. They later manage to get Nevin a permanent job at the bakery, forcing the gang to look elsewhere for laundering money due to cops frequenting the area. Tim receives his sergeant exam results, but turns down the offer of starting in North Hollywood, in favor of finishing training Lucy. Nolan meets his half brother Pete (Pete Davidson) while working his and Harper's case, who twice steals the car he inherited, but they manage work out a better relationship, and Pete begins a relationship with Chastity.

Lopez and Jackson are called to a man who is shot in the top of his head and seems to ramble. Tim and Lucy are called to a couple, where the wife reports to being stalked by a drone. The husband takes it further when he shoots down the drone the next time it appears. The boy responsible shows the footage to Grey, who reports to Lopez and Jackson that both their and Tim and Lucy's cases have been solved. Nolan and Harper chase a suspect into a warehouse, where a body, identified as Joe Delacruz, is discovered. They search the victim's hotel room, and encounter an Afghanistan war veteran, who attempts to flee before Tim and Lucy arrive. Tim is revealed to have been the veteran Mitch's commanding officer when they served together. Together with Armstrong, they search the warehouse again for evidence of counterfeit money according to Mitch, but find it empty. Grey, on orders from higher ups, orders them to let the case rest. Deciding against it, Tim calls LA Clear, and learns that the DIA is behind the counterfeit related to an ongoing operation. Nolan is confronted by Norman Jangus, the main man of the operation, at his home. Tim, Lucy, Harper and Nolan arrive at the docks and discover further counterfeit until they're confronted by Jangus and his crew. Tim makes Jangus give up who killed Joe Delacruz and decides that they should look away from the counterfeit. Lucy decides to have a dog, much to Jackson's annoyance. She later gives the dog to Tim, deciding she is not ready to have one yet.

Nolan's identity is stolen and he works to restore his credit score to remain a police officer and get his money back to fund Henry's college tuition. He and Harper are able to track the identity thief (Seth Green) using one of the purchases made under Nolan's name, but later have to track him down when one of the other people whose identity he stole kidnaps him for his money back and severs his hand. Nolan and Harper are able to save the identity thief and in return for his gratitude, he gifts Nolan a secret comic book collection he purchased with his money so that he can get his money back. Grey and Lopez head to Lompoc Prison to testify at a parole hearing for a man who shot Grey and his partner Dennis Rowland, who died in Lopez's arms her first day on the job, something Lopez still has nightmares about although she remarks they're not as bad as they used to be. On the way there, Lopez reveals that she had smelled alcohol on Rowland's breath as he died, which shocked Grey as he believed Rowland was sober for four months. Despite the man's parole being denied, Grey votes in favor of parole after interacting with the man and his son. While Grey and Lopez are at the hearing, Jackson is assigned to make sure the station is in compliance with all guidelines, during which he finds an unassigned unsolved vandalism case which leads to him solving a homicide. Tim meets Rachel's father, a former sheriff of a small town who reveals he does not want his daughter marrying a cop, especially since there's a chance Rachel might have Huntington's disease.

Lucy and Tim respond to a call at the Los Angeles auditions of "American Idol" and Lucy ends up facing Ryan Seacrest and the judges. Lucy befriends a reporter (Roselyn Sanchez) whose motives are not clear, and later she and Tim have to save the reporter during an arrest. Harper asks Nolan to come along with her to her ex-husband Donovan's home to help her daughter who is having trouble sleeping. This leads to Nolan's life being put in danger during a domestic dispute with one of Donovan's neighbors. At the end, Wesley proposes to Lopez and she accepts his proposal.

Note: This episode includes a joke referencing Melissa O'Neil's victory on the third season of Canadian Idol.

Nolan and Harper encounter Nolan's former C.I. Bianca, and she tells them that Ripper has returned with a large shipment of fentanyl. DEA Agent Michael Banks (Bailey Chase) arrives and they determine that Nolan and Harper must go in disguise to confront Ripper. They successfully agree to meet with Ripper, but everything goes wrong when Bianca confronts Ripper and tells him about the operation, but she is abducted. Meanwhile, Lucy meets a firefighter, Emmett, during a call and is intrigued by him. Lopez also interrogates a bank teller after a woman is murdered, and clashes with Detective Calderon on how the case should be handled. Banks offers Harper a job with the DEA after they successfully rescue and arrest Bianca, but she respectfully declines his offer.

Nolan and Harper are tasked with escorting four juvenile delinquents to a correctional facility, but find themselves entrapped in a prison riot during their processing. The pair find themselves forced to make an unlikely alliance with Oscar Hutchinson in order to safely evacuate their detainees from the prison, as well as saving the warden from the hostage situation. Meanwhile, Rachel and Tim have to rectify a mistake that caused a mother to lose custody of her ailing child after learning that a compromised water system was the cause of his sickness. Lopez and Jackson have to escort a tech analyst who has flagged Lopez as an officer most likely to cause problems in the department, and also have to subdue an active shooter at the tech analyst's office building.

When a fellow rookie colleague Chris Rios (Christopher O'Shea) is fatally shot in broad daylight by a member of the Derian crime family, the entire police department commences a manhunt where multiple complications arise. Tim and Lucy raid the gunman's house and learn that an L.A.P.D. officer is on the crime family's payroll; Nolan and Harper recover the murder weapon from the crime scene, but find out it is stolen after a raid on Ruben Derian's residence; Jackson deals with the aftermath of Chris's death at the hospital while Lopez attempts to search for the mole. While viewing through the officers' body camera footage, Lopez learns that rookie officer Erin Cole (Hannah Kasulka) did not have her body camera function at all during her shift, with the Wilshire precinct conducting another manhunt on Erin. Nolan encounters a guilt-ridden Erin by himself and learns that she was the actual target of the assassination attempt, with Chris being collateral damage. Despite Nolan's successful attempt in calming her down, Erin is fatally shot by Armstrong. During the aftermath and inspired by a recent conversation with Harper, Nolan reviews his body camera footage and deduces that Armstrong was the actual mole working for the Derian family, and was working with (and betrayed) Erin.

Harper agrees to help Nolan after he shows her the body camera footage. They lead Armstrong to an abandoned house to pick up his burner phone's signal in order to tap its records to uncover evidence of his crimes, but discover he had tossed it. Left with no other choice, Nolan returns to Rosalind Dyer, who reveals that, after Armstrong had broken into her house (as he had revealed to Nolan) to secure evidence to arrest her, she broke into his and found a stash of guns, cash, and files that incriminate Armstrong. Nolan breaks into Armstrong's house and locates it before escaping, but Armstrong sees him as he departs. He alerts Serj Derian, who is arrested after a raid on his house. Armstrong invites Nolan back to his house, explaining that he got in too deep with the Derians once the costs for his deceased wife's medical bills became too much for him to handle. Armstrong reveals that he plans to incriminate Nolan as the mole before Nolan incapacitates Armstrong in a shootout, who reveals that he planted his stash in Nolan's house as Serj tells Grey that Nolan is the mole. Nolan finds the stash hidden inside a wall in his bedroom. The season ends on a cliffhanger with Nolan standing in his bedroom as the police close in on him.

As Nolan finds the stash planted by Armstrong, Grey asks him to step out of his house but Nolan demands a warrant to enter first in order to buy time to hide the stash and also calls Wesley to act as his defense attorney. As Wesley is getting dressed to contest the warrant, he knocks over a wastebasket and finds a positive pregnancy test. As Armstrong is brought to the hospital, he implicates Harper as an accomplice of Nolan, but has the tables turned when Harper explains Armstrong's corruption to Internal Affairs Commander Percy West and Lopez is able to find Armstrong's go bag off of a tip acquired from Rosalind Dyer. Nolan attempts to clear his name by going undercover to catch Ruben Derian in order to implicate Armstrong, but his cover is blown when Armstrong escapes from the hospital and makes a deal with Ruben after getting tipped off by Rosalind about the cops finding his go bag. As Armstrong prepares to execute Nolan, the gun he is given is revealed to be empty and he is shot dead by the gang members as part of a cover-up; Nolan is able to escape and place Ruben under arrest. In the aftermath, Nolan and Harper both receive letters of reprimand in their personnel files and Nolan will be held in the training program for an additional month and must pass a disciplinary exam with the reprimand also ruining any chance Nolan has of becoming detective or even joining a specialized unit in the LAPD. Lopez receives a promotion to detective and opts to hold off on announcing her pregnancy out of fear that she'll be treated differently as a rookie detective.

As punishment for their part in the Armstrong fiasco, Nolan and Harper are assigned to a community policing center with the hope of rebuilding their station's reputation. While Nolan tries to make a positive impact, Harper has her doubts regarding his methods. Meanwhile, Lucy tries to find the person who stole her car, and later tries to help her upon learning of her situation. Jackson gets off to a rocky start with his new training officer, Doug Stanton, who is revealed to be prejudiced against black people, and Lopez's first case as a detective is a difficult one as someone broke in to use a furnace to cremate a body. She later discovers that the body is one of many burned on the orders of a notorious gang.

Nolan's life becomes more difficult when his mother (Frances Fisher) visits him. Distracted, Nolan fails his firearms re-qualification exam, and later stumbles upon a plot to assassinate a businesswoman with shady connections, La Fiera (Camille Guaty), when he returns to practice for the retake. Lopez, Nolan, Tim, Lucy, Jackson, and Doug successfully thwart the assassination. Also, Jackson and Doug continue to exchange blows when Doug opts to arrest an entire family who were not even connected to the crime the suspect that they're looking for committed. Jackson reports Doug to Grey with Tim's backing, but Jackson is outraged when Grey says that Doug will only be assigned to administrative duty. Grey later admits to his wife Luna that he and Jackson need to solve the issue with Doug.

As Grey and Jackson look to shut down Doug, Nolan and Grey are looped into a scam that their family members put money into—instigated by Nolan's troublesome visiting mother. Doug sets up Jackson by making it look like he was going to beat up a kid, but instead writes him up for failing to stay with the evidence after Jackson ran after him. Lopez is shocked when Wesley reveals that he is predisposed to fragile X syndrome, which could mean that their child could suffer mental disabilities and seizures. At the same time, Lopez confronts her supervisor, who she believes is not assigning her cases because of her pregnancy. Her supervisor, who was unaware that she was pregnant, tells her that's not the case, but it doesn't mean that he will be easy on her. Increasingly troubled by his mother's interference in his life and career, Nolan finally forces her to leave permanently.

As Nolan passes his disciplinary exam, he is once again reminded that he has a very little chance of ever getting promoted. He is later held hostage by a man (Josh Stewart) who threatens to blow up the police station unless the release of a dangerous felon happens, but Grey and Harper do not buy it and start to look for the real motive. Jackson and Doug reach a point of no return when Doug threatens to report a fireable offense against Jackson, with Jackson firing back that his father, the head of Internal Affairs, would rip apart Doug's career. Doug sets up Jackson to take a beating in a public housing complex, but it backfires when Jackson activates Doug's body camera, showing that Doug did not intervene in the beating. Doug is placed on suspension. Since he has no chance for a promotion, Nolan sets his sights becoming a training officer, which requires him to complete his degree.

Lucy gets a taste of what undercover work is like when she works with of Harper and her Fresno PD colleague June Zhang in a narcotics operation, much to Tim's chagrin. Lucy's initial success brings her onboard an operation to take down Aldo Salonga. Nolan's return to school becomes difficult when he is outed as a police officer in his ethics class. After asking for advice from Tim and Harper, he is still unsure if it was a wise decision, and asks his professor, who expresses that one should be open, and that the other students will accept him again. Jackson befriends a mounted police officer, Isaac Young, while working with Smitty at the community policing centre. Tim, while working security at the undercover convention, meets a colleague, Mack Daniels, who appears to have an addiction problem—and an involvement in an extramarital affair. Despite taking firm action on Mack's behalf to help him, his trust with Mack's wife, Beth, sinks.

In a true crime documentary, the station breaks down a recent case of a former child actor, Corey Harris (guest star Frankie Muniz), known for his role in the fictional show Paul's Place, who turned into the leader of a cult. Said cult is revealed to be the same one Lopez and Jackson encountered previously. Harper and Nolan initially responded to a call where Corey was reported by a girl's father, before Nolan convinced the girl, Debbie, to stop. Corey is later reported missing after his house becomes a crime scene, with blood later identified to his former co-star, Charlotte Luster, and a mummified body of Charlie Chaplin is found under his bed. Charlotte is also reported missing, and her car found at LAX. Corey is later found alive, and remains silent for five hours before demanding a lawyer, revealed to be Wesley. Corey's mother is arrested after CCTV shows her parking Charlotte's car. She also confesses to the murder and claims sole responsibility. Corey himself is later murdered during a livestream to his followers, by Ronald Sanchez, a former student of his.

Nolan struggles to find the answer to a question he needs in order to take an exam for his ethics class. Lopez, Nolan, and Harper must work with Oscar Hutchinson (Matthew Glave) to find his previously unknown daughter (Molly C. Quinn), who is involved in the kidnapping of a judge's son. Tim looks for the tagger 3Eyez, who spray-painted his squad car as a rookie after the tagger resurfaces from retirement. He later discovers that she only came out of retirement because she wanted to feel young again after breaking up with her husband. Jackson is put in the middle of a debate between Grey and his father when the two argue about what Jackson should do once he completes the officers' field-training program. Jackson decides to accept advice from them both but makes it clear that it is too early for him to decide his career path. Nolan presents his answer to Professor Fiona Ryan, concluding that, based on insufficient information, all the given options would be wrong. She decides to let him take the exam.

In what is Lucy and Jackson's final day as rookies, the department races against the clock when a newborn is kidnapped from the hospital. Nolan and Harper do a ride-along with Nolan's professor Fiona Ryan, who is working on a book about police reform, and Lopez, who is riding with Jackson on his final day as a rookie, contemplates what her future as a parent holds. She is reassured by Jackson and gets some advice from Harper during the search. The baby's father is later found after he crashes his car, but he is revealed to have never taken the baby. CCTV at the hospital reveal that a woman, Rita Cissane, kidnapped the baby after her own died of SIDS. They later find her on a bridge with the baby, and Nolan and Lopez manage to convince her to give up the baby. As Lucy and Jackson celebrate their last day as rookies, Harper invites Nolan for dinner with her and her daughter to cheer him up.

Jackson and Lucy become full-fledged police officers. Jackson celebrates, but Lucy is hurt when her mother tries to get her to abandon her "thankless job". Ben comes to visit Nolan and reveals that Henry now works for him, which means he has dropped out of college. Harper feels awkward when she sees someone from her past. Tim assists Lopez with preparations for her and Wesley's wedding, and assures her to plan her own wedding the way she wants it. She later has him take over as her man of honor. Nolan responds to a call where a man is holding people hostage. He has the situation well in hand, but a nervous security guard shoots and kills the man. He later continues the investigation into the case with Harper's help. They discover that the man's family were disturbed by robbers who forced him to pay back, prompting him to rob a bank. His wife and daughter are abducted and the assailants force the wife to steal from her workplace. Nolan assists her while Harper causes a distraction, giving Lucy and Jackson enough time to find the daughter.

Nolan watches over Fiona, after threats escalate from a brick through her car window and harassing messages to a shootout with white supremacists in the middle of a street in broad daylight. As the new rookies arrive, one named Larry "the Badger" Macer—who fawned over Nolan, saying Nolan's academy success inspired him in turn—accidentally fires his gun, which ends his police career before it begins. Lucy becomes jealous of the way Tim treats the second rookie, Katie Barnes, a former female soldier who he tries to help readjust back to civilian life. Katie resigns at the end of the day, saying she needs to find her way. Tim assists Lopez and Wesley in planning their wedding, acting as a third party when Wesley's mother comes over to look over the plans. She later reconciles with Lopez and urges her to plan her wedding the way she wants it. Henry returns to Los Angeles to begin his new job, with Nolan struggling to be supportive of his son's choice to leave school. He becomes more accepting of his son's decision after a talk with Fiona, but then Henry collapses at dinner.

Henry is rushed to the local hospital following his collapse, caused by a lifelong medical condition. He has a heart attack before he can decide whether to undergo a safe, short-term repair or long-term surgery with a 20% mortality risk. Nolan chooses the long-term option, believing Henry would have wanted that. The gamble is successful. La Fiera has taken her injured son, Diego, to the same hospital, but the police soon realize she is actually there to negotiate an agreement with a major drug dealer, Tomás Madrigal, who is close to death and knows his son is incapable of running the business. Harper surreptitiously records the conversation. Lopez unsuccessfully confronts La Fiera twice, trying to warn her off. Billie, an addict slightly injured when arrested by Jackson and Lucy, is made to admit she is a drug mule carrying MDMA in her stomach and is offered a deal. When a condom bursts, she is taken for life-saving surgery. Tomás' son, Cesar, orchestrates the murder of La Fiera's son, Diego, who is shot and killed in the underground parking garage at the hospital but La Fiera is protected by Lopez in the ensuing gunfight. After La Fiera grieves over her son, Lopez predicts a drug war is coming. Mack Daniels has been reduced to temporary security work for the Madrigals, and Tim offers support for his addiction.

La Fiera starts her war by massacring Cesar's men at a drug deal but comes to the attention of a DEA task force. Lopez negotiates with her to cease hostilities in exchange for Harper's hospital tape, which will convince Cesar's lieutenants of the agreement's validity. Tim and Nolan conduct a stakeout of Cesar's girlfriend's house and prevent La Fiera's men killing her baby as revenge for Diego's murder. DEA agent Taggert tries to belittle Lopez. He obtains the tape over her head and has Lopez deliver it, but La Fiera sees through his stratagem of including surveillance malware on the USB stick containing the recording. The war highlights a need for undercover work so Harper puts Lucy though a series of intense tests: a social gathering with "criminals", a drug-cooking session and a phoney attempted kidnapping. Offered a last chance to pull out, Lucy remains determined to go undercover. Jackson learns Doug is still on the force and has not changed, despite everything that has happened. He threatens to go public even though Grey thinks it may cost Jackson his career. Instead they improvise, by having Doug's watch commander use Doug's and Jackson's body-cam footage as a so-called retraining video to expose him which has his colleagues shocked and Jackson grimly remarking that this is the real Doug Stanton.

The possibility of making Cesar Madrigal an informant against La Fiera is floated, and Nolan approaches Cesar's girlfriend about persuading him to talk. However, just as Nolan and Smitty locate Cesar, he is fatally shot by a sniper. Later, on patrol, they chase a shoplifter who, after being arrested, is unjustifiably charged with assault instead of a simple misdemeanour, on the grounds that Nolan had accidentally dislocated his own thumb during the pursuit. Nolan brings Professor Fiona Ryan into the case and manages to get Grey's backing to force ADA Sean Del Monte to reduce the charge. Lucy starts her undercover work in a rundown motel and is duly grabbed by Aldo Salonga's brother Dahrio, who forces her to participate in a robbery to obtain ingredients for the drugs he wants her to cook. Her work is interrupted when La Fiera storms Dahrio's compound to force him to join her cartel but the police, alerted by Harper, arrive to arrest the gang. Lopez forthrightly tells La Fiera that she has only herself to blame for her son's death. La Fiera is later broken out from her prisoner transport, and as Wesley and Lopez's wedding ceremony begins, Nolan enters the room and discovers Lopez's bracelet on the floor with Lopez herself missing, having been kidnapped by La Fiera's men.

In the midst of Lopez's kidnapping, Jackson is killed by La Fiera's men while trying to save her. Grey and Wesley enlist the help of the DEA, but they are bound by the political ramifications of the case. Nolan, Tim and Harper enlist Max, who gives them a helicopter and arms to rescue Lopez, who has been brought to Guatemala. Wesley receives help from a criminal, Elijah Stone, in exchange for future favors before travelling there himself to make a deal with La Fiera. La Fiera threatens to kill Lopez once her baby is born. Nolan and the others resort to their backup plan. Wesley is separated from Lopez as she is brought to the hospital in a staged labor. Tim and Harper ambush La Fiera at the hospital and save Lopez, who shoots La Fiera dead before they escape in the helicopter, avenging Jackson. Nolan saves Wesley from La Fiera's remaining goons. Three months later, Lopez has given birth to her and Wesley's son, who they name Jackson in honor of Jackson West.

• Due to Titus Makin Jr. departing from the show after the third season, Jackson West is played by an uncredited stand-in during security camera footage of his death.

Tim is promoted to Sergeant and leads the roll call as a new rookie, Aaron Thorsen, is handed to Harper. Harper is convinced Aaron does not have what it takes to become a cop, as he is suffering from memories of his trial for having allegedly murdered his roommate in Paris. However, Aaron takes on the courage to be motivated to become a cop, convincing Harper to change her mind. Nolan and Lucy pull over a notorious thief, Claire Ivey, for speeding, and she gives them a clue for an upcoming robbery. The department conduct a stakeout against Claire and her crew and manage to prevent the robbery by disguising themselves as the targeted convoy. Nolan gets the nerve to ask firefighter Bailey Nune out for a date, to which she agrees, but after a night together, she initially breaks up with him. Afterwards, he manages to convince her that she can change and try out a first relationship.

Nolan and Lucy respond to a house fire and rescue a man trapped inside. The LAFD discovers a body inside after the fire is put out; an autopsy reveals that he was killed before the fire occurred. While on a break, Nolan, Lucy, Tim, Harper and Webb witness a sniper shooting at a private escort vehicle. The sniper escapes, and Harper and Aaron discover that the sniper has military experience. Nolan and Lucy investigate a suspect pool and question Aidan Merritt, who briefly holds them hostage in his own home before Nolan subdues him. Caught in debt to crime boss Elijah Stone after Lopez's rescue in Guatemala, Wesley is forced to work for him, putting his career at risk. Elijah assigns him to defend Aidan. Lopez investigates the fire and the suspect pool, revealing to Nolan and Bailey that multiple similar fires occurred in Nevada, suggesting a serial killer is on the loose.

Lopez returns to work, while Nolan investigates an alleged home dispute where a wife has escaped from her husband's house. Nolan later finds the woman, Linda Charles, walking in an alley, disoriented and speaking a foreign language. The husband and his assistant arrive and pull guns on them as Nolan's suspicions are heightened. All three of them are later revealed to be Russian agents, with Linda Charles, real name Katerina Antonov, having gone rogue. Harper and Aaron investigate a hit and run involving a bike, where the biker was taken away by the driver. Harper tracks the stolen car to a warehouse, where she finds the victim knocked unconscious. As she is about to run after the suspect, the warehouse is caught ablaze, but she manages to escape with the victim. Nolan and Bailey discover a chip that Katerina lost in his patrol car, only for her to hold Bailey hostage. They manage to break up the fight until the FBI arrest Katerina. Lopez concludes that the warehouse fire was caused by the same assailant from the previous episode. Elijah Stone has Aidan Merritt killed after Wesley can't work out a way for him to be released, serving as a last warning to him.

Halloween in Los Angeles has Nolan and Harper detaining a crazed person in a park, in what initially seems like a zombie attack. They learn at the hospital that the woman took a drug, Bomb-X. Lucy assists a neighbor with two ghost hunters who wants to charge her more money than what she can afford. Lopez is handed the case, but the victim, Mrs. Crouch, later decides to drop the case. However, Lopez does learn that the apartment building is in fact haunted. Lucy and Tamara investigate the alleged ghosts that the ghost hunters mentioned, only to discover another neighbour being attacked by a stalker. Lucy manages to stop him. Tim encounters another person affected by Bomb-X. He and Nolan enlist Nolan's half brother, Pete, to wear a wire to buy the drug, and they later catch the supplier. Nolan later helps Pete reconcile with the latter's girlfriend.

Tim is tasked by Grey to talk veteran officer Jerry McGrady into retiring, and Tim decides to take Jerry with him on patrol. Nolan, Lucy, and Harper start investigating a treasure hunt, based on a cryptic poem which Nolan and Harper found with a suspect. Tim and Jerry join the hunt, as evidence from an old case worked by Jerry proves to be connected to it. They decipher the poetic clues, which lead them to civilians harming each other, also in the hunt for the treasure. Nolan, Harper, and Lucy track the clues to an old abandoned 1920s subway, and are forced to tackle two men who end up in a brawl. The station bids farewell to Jerry after he announces his retirement himself. Jerry's daughter Ashley hints to Tim that she's interested in him. Nolan, Bailey and Lopez continue the investigation into the previously mentioned serial killer, who Nolan suspects to be Bailey's lieutenant, Fred Mitchell, after he discovers acetone similar to the one used by the killer in his garage, and Bailey searches for evidence in his house. Just as the police arrive with a search warrant, Fred's house explodes.

Bailey is severely injured in the explosion and has to use crutches. Lopez, Nolan, and Harper reopen the serial arson investigation after a colleague of Bailey reveals that Fred was in the hospital in Nevada at the time of the murders. They also conclude that the real killer was trying to frame him. Tim and Lucy investigate several cases of alleged illegal substances used in makeup and skin cream, and one of the rivals reveals that the other is planning to have her husband killed by a hitman. Tim goes in undercover as a hitman and arrests the woman in question after she admits to it. Nolan is captured by the real killer, revealed to be Fred's neighbor, Marcus. Nolan is subjected to a cat-and-mouse chase in an abandoned silo complex, eventually escaping and running Marcus over, arresting him in the process. Wesley continues his dealings for Elijah Stone, notably discrediting a witness. Having reached his limit following a near-beating from Elijah, due to a lack of communication on his part, he eventually comes clean to Lopez.

Lopez asks Wesley to record everything when in contact with Elijah Stone, but he refuses due to client confidentiality and privilege. Nolan and Lopez arrive to talk to "sovereign citizen" Marvin Reynolds, but he shoots at them and escapes, becoming a wanted felon. Tim's sister Genny arrives in Los Angeles to sell their father's house. Harper and Aaron search Marvin's RV, where they discover weapons and a manifesto. Aaron also gives Harper advice when she reveals that her ex-husband wants to move with their daughter to San Francisco, and Harper decides to fight the custody battle for her daughter. The police corner Marvin at the Battleship USS Iowa Museum and eventually shoot him. Tim decides to join Genny in renovating the house, but refuses to visit their father, and also officially endorses Nolan for union representative. Lopez builds a RICO case against Elijah, but learns that Wesley told Grey and that they plan to use Wesley as an informant.

Tim and Lucy assist his sister, Jenny, with refurbishing their childhood home. Tim discovers a gun in a wall, and he and Lucy open an investigation. The gun was suspected to have been used by Tim's father in a botched home invasion 25 years ago. His father had an affair with the neighbor's wife; she later confessed to having shot her husband in self-defense, and Tim's father helped her cover it up. Tim visits his father on his death bed, but still doesn't forgive him. Grey initiates Wesley’s wiretapping operation, but his cover is blown by Elijah, who threatens Wesley's family. Sometime later, Elijah and his crew are attacked by a rival gang, which Elijah reveals to be led by La Fiera's security enforcer, Abril. Elijah is arrested shortly afterwards, and Abril warns Lopez not to hunt her down. Nolan has Bailey meet his son Henry for the first time, and considers proposing to her, which Henry approves of. However, as the two are out eating, a man walks up and reveals himself to be Bailey's husband.

Nolan is heartsick over learning of Bailey's marriage to Jason Wyler, an embezzler and con artist who abused her psychologically, and who has just been released from prison early for good behavior. A jarring small plane crash on the streets has the precinct staggered when no pilot is found. The plane's owner, billionaire Levi Lincoln, convicted of murdering his wife, turns up alive and having paid another man a small fortune to serve his prison time for him. Wesley's law license is suspended for six months over his forced dealings with Elijah, but his volunteering legal counsel at the community center takes a troubling turn involving a youth trying to free himself of a drug dealer's grip. Tim asks Lucy's help teaching the dog she gave him to get along with Ashley McGrady after their relationship becomes serious. Bailey confronts Jason and demands he make good on his promise to sign off on their divorce at last. Nolan is forced to turn to Oscar Hutchinson yet again to gain information on both Levi and Jason. Nolan and Harper lead the precinct in capturing Levi at a small private airport following a shootout in a hangar. Jason plants drugs in Bailey's car and she's arrested. Nolan tells Bailey he loves her no matter what and will help set her free before confronting Jason himself.

Grey authorizes an investigation into Jason, and Nolan turns back to Oscar Hutchinson for further help along the way. Lucy and Tim investigate the murder of an 18 year old girl, Becca, who turns out to have been a friend of Tamara Colins. They learn that Becca had stolen a watch from a man she met on a social media app, and pawned it at a pawn shop. The shopkeeper also gives them the name of the perpetrator, Declan, who in turn was also a friend of Tamara and Becca. Harper discovers she is pregnant with James’ child, and she is determined to keep it. Aaron struggles to decide if he wants to shoot a reality program with his mother to give his narrative of Patrick's murder, which he later decides to do. Nolan and Bailey expose Jason's motives to another woman, leading to him turning himself in and cooperating with the police in an undercover mission against the Southern Front. However, Oscar informs Nolan that he pulled a double-cross by informing the criminals about Jason, leading to Jason attempting to flee among the chaos, but eventually being arrested by Nolan.

Nolan is elected as the station's union representative, aiming to accomplish changes, which is met with antagonism from the union president, Lt. Landon Briggs. Lucy and Tim discover a severed hand on the beach, which is identified to have belonged to Mark Klinke, who had managed to get himself to a hospital before dying. He worked for a biotech company, headed by Devin Swaine, who is reluctant to reveal any further information due to confidentiality. His lawyer, in a desperate attempt, tries to seek access to the culprit, Chester Frey's house, which Lopez denies. The police discover that Chester had obtained multiple human arms to test if they could be healed and animated. Tim and Lucy ambush him in the morgue and arrest him. Grey accompanies Italian detective Romeo Cabarelli in a hunt to find wanted fugitive Kai Zullo; however, upon them finding Kai, Romeo fires on him without signs of him pulling a gun. Grey becomes suspicious. Romeo is revealed to be under investigation for misconduct in Italy. Grey, Nolan, and Harper trick him into an arrest of Kai, leading to Romeo's own arrest in addition.

Nolan and Lucy pursue a stolen police helicopter, which 17 year old Leo Thomas stole after meeting Nolan in the garage. Leo refuses to land until they fulfill three quests of his, the first of which includes a known drug house, where they arrest and send the occupants to the hospital. The second one includes a man connected to his stepfather who was dealing drugs and owns an alligator. Leo's third quest seems initially difficult, in which he wants them to arrest his stepfather. Grey manages to get the alligator owner to give evidence against Leo's stepfather, who is then arrested. Leo is also arrested once the helicopter runs out of fuel; however, he is released on bail shortly afterwards. Tim and Lopez investigate a string of burglaries with ties to a friend of Tim, Des Robinson, who gives up the robbers' identities. However, they find further evidence connecting Des to the robbers, before arresting them in action. Aaron and Harper guard an escaped convict at the hospital, who allegedly killed a cop. Aaron is convinced of his innocence, and calls in James and Wesley to assist. CCTV footage from the prison proves that the convict stomped a guard during the riot, and will be arrested for attempted murder. Wesley manages to get a lawyer who wants to take the convict's case, making Aaron hopeful that he can be proven innocent for the murder of the cop, and only face the charge of attempted murder.

Skip Tracer Randy arrives at the station to meet Nolan and Harper about a bounty on a notorious Madam, Ivy Flynn, whom he sets out to capture, teaming up with them. They roll out on a sting operation, where another bounty hunter, Alicia Kaufman, is about to apprehend Ivy before she escapes amid arguments between the four. Alicia is revealed to be Randy's lover who shares the same goal: to capture Ivy. A vice investigator tells Nolan and Harper that Ivy had wealthy and powerful clients, in addition to having received funding from organized crime. At a hotel, they find and arrest Ivy, but are attacked. Alicia arrives and takes Ivy for herself, but Nolan assists her when they are ambushed in the parking garage. Lopez recommends Wesley for a legal consultant role in a new TV series, but the lead actress' odd behavior puts him on edge. Tim and Lucy look for Jordan Conner, who unleashed rats in the restaurant where she worked after getting fired, and threw a Molotov cocktail into her ex-lover's car. When they find her, she reveals she had cancer before learning it had gone into remission. She describes her own actions as karma against people who wronged her. Lucy tries to find her biological father, and learns from her aunt Amy that he was one of her mother's therapy patients who she had a relationship with, and that he is dead.

Aaron's Plain-Clothes Day gets tough when he and Harper discover his mother's film crew following them. He later encounters the father of Patrick Hayes, the friend whom he was accused of having killed; Aaron is forced to arrest Patrick's father after he tries to punch him, but decides to let him go out of respect. As Grey is heading to court to testify in a case against a powerful mobster, a woman is killed in a drive-by and a man is poisoned at the station, both of whom are revealed to have been witnesses in the same case that Grey is testifying in. He is shot and wounded by a female assassin, who he manages to fatally wound. In a raid, the LAPD uncovers burned documents that points to attorney Kellen Myers, who Lopez learns sold the names of the witnesses and the prosecutors to Mateo Rubio in exchange for money. Kellen also reveals that Assistant District Attorney Sean Del Monte is on the hit list. Del Monte and Chris Sanford manage to avoid a second assassin and hold out until Tim, Lucy and other officers arrive to apprehend him. Grey contemplates retirement when he awakes in the hospital and soul searches with help from Nolan, returning the favor Grey did him after Nolan's first on-the-job kill. Bailey attempts to paint a portrait of Nolan, which he agrees is terrible.

Aaron reality show crew interviews precinct officers about the crime investigation after the show's director, Morris Mackey, is murdered in Aaron's parents' home. Aaron himself is among the suspects. The documentary also brings up the murder of the second half of his father's rap duo, which is still unsolved. Patrick Hayes' father is also questioned, as are Aaron's friends who were with him in Paris. Patrick's case is brought back into the spotlight when the police suspect the murders are connected. Aaron's mother is also revealed to have been in Paris when Patrick was murdered, but reveals she had a sexual fling with a French footballer. The French investigation into the Hayes murder is criticized for its lack of attention to other suspects, one of them being the finance minister's son. The police eventually conclude that Aaron's friend Rowan Clausen committed both murders, having always been the instigator for friend activities and opportunity in order to use the latter to smuggle drugs on Aaron's private plane; Rowan killed Patrick for discovering and threatening to out his smuggling operation, and then Morris for figuring out he was behind the first murder. In the end, Patrick's father asks for forgiveness, which Aaron accepts.

Nolan is first on the scene of a car accident whose lone occupant suffered catastrophic injuries, but is still conscious. He talks with her as she dies. She's an organ donor, so he accompanies her body to the hospital. A teenager is first in line for the victim's heart. Harper is at the same hospital due to potential pregnancy complications. Lucy is scheduled to give a deposition about her kidnapping for additional charges against Rosalind Dyer. Things start going wrong at the hospital because a man hacked the system to put his wife first on the list for a transplant. Officers try to talk him and his wife out of their plan, but fail. Despite instituting contingency plans, patients start dying and the hospital agrees to give the heart to the wife. Nolan lets the other recipient talk to the wife, who changes her mind and backs out of the plot. When the hacker tries to release the hospital, his ransomware partners switch to a pure money demand. The officers find them and upon the two being arrested, the hospital returns to normal. Harper closes an ongoing kidnapping case and after some rough times, Lucy decides not to contribute to the case against Rosalind.

Nolan and Lucy join forces with Larry "The Badger" Macer, who is now working for the railway police, in investigating the robbery of a cargo train, where a vase was stolen from a freight car belonging to millionaire William Bloomfield. Together with Lopez and Harper, they learn that William's cellmate, Brian Shab, stole the vase, but is later found dead in his home. William himself points them towards his own teenaged children: Francis, Danielle and Zachary. Larry deduces that a missing piece of the vase had a bank account number on it, which might have been the motive for it to be stolen. Nolan, Lucy, and Larry return to the train yard after a burning car on the tracks is called in. There they find not one, but all of William's children fighting over the money, and Danielle and Zachary point to Francis being the killer. Aaron struggles to find his "superpower" while patrolling with Tim. But after talking down a man on parole from visiting his child, Tim notes that his experience from being in jail gives him the ability to sympathize with people who experienced the same. Harper proposes to James, but he becomes uncertain afterwards due to how suddenly she did it. In the end, they agree to marry and the wedding is attended to by family and friends.

Nolan and Lucy respond to a call of a suspicious person near a power station, which they quickly realize has a bomb in before they escape before it detonates. The FBI's Los Angeles division is called in when it is suspected that the bomber belongs to a terrorist cell. When the FBI learns that the suspect, Zeke Freemont, has a connection to FBI trainee Simone Clark (Niecy Nash), they call her in to assist, but is soon dismissed. Nolan encourages her to stand up for herself and they find common grounds with both having been the oldest trainees in their respective agencies, both the LAPD and FBI. Lead agent Matt Garza calls her in to question Zeke as he only wants to speak to her. He reveals that he built bombs for the bomber, but did not know what they were for. Lopez and Harper investigate a supposed break in at a professor's house, and with Simone's help, discover that it was the same suspect as with the bombing, who is later identified as Trevor Gurin, with a classified connection to Groom Lake. With reluctance, Garza takes Simone on to his team. Through map evidence at the suspect' house and the codeword "Enervo", they deduce that Trevor was former military. He steals further bombs from the National Guard's weapon storage, and initiates his plan to take down the city's infrastructure, starting with the roads.

---

This episode is a crossover with The Rookie: Feds.

The Mid-Wilshire station and the LA Division of the FBI race to stop bombs that have been scattered throughout the city on board separate vans. Deducing that the targets are every freeway, Simone leads herself and Nolan in the direction of one of the trucks and narrowly sideswipe it just before it reaches a freeway bridge. Grey and Garza take to the skies courtesy of an FBI chopper to get an overview from there, while Tim and Lucy and cavalcades of LAPD and FBI manage to stop the remaining vans, although one still detonates, killing 17 people. Garza and Grey approach the LA CIA station in hope of help, but its chief, Bill August, turns them down, though promises to look into the classified file on Trevor. Tim and Nolan meet one of the former's former associates, Kate Hill, who works for the CIA, who are quick to shut them down, but are shut down by the LAPD in return. Kate reveals that "Enervo" was a black Ops designed to destabilize foreign cities, headed by Bill and the lead perpetrator being Trevor, whose real name is Ilya Sokorov. Simone follows a lead with the help of Zeke identifying a Russian chocolate bar Ilya had. She meets him near the aquarium before the two fight before Nolan arrives. They track Ilya into the aquarium, where he explains that Bill deserted him and his crew and left them for dead, and his acts of terrorism was revenge against Bill. Just then, Bill's men arrive and a shootout ensues as they flee outside, where the LAPD and FBI arrive to arrest Bill's men.

---

This episode is a crossover with The Rookie: Feds.

Grey expresses support for Nolan's desire to become a training officer, but warns him to expect retaliation from the union President after standing up to him earlier. They respond to a call at a film set, where Sabrina Fowler explains that another woman, Monica Ditmar, attempted to steal something from her, and they set out a BOLO for her. Tim and Lucy respond to a call of a guard escaping in a Porsche with car and keys of rich people, and Lopez and her mother-in-law are victim to a robbery at an expensive dinner. As the three investigations merge, Lopez, Harper, Tim and Lucy realize that both suspects are connected, and thereby all actions were planned. Grey and Nolan clear an apartment and the surrounding areas to set up a boundary for Daniel Tran, a gang informant, who has decided to enter witness protection. DA Sean Del Monte reluctantly allows Daniel to visit his mother, but he escapes protection to do so. As Grey and Nolan find him, they take out two men sent to kill Daniel, while he escapes and a third one sneakily follows. Nolan manages to disarm him and save Daniel. Tim and Lucy discover Monica and her husband Jonah Cahill, to a church, where they force forward their own wedding, but as Monica spots them, a shootout occurs. Jonah is shot and injured, while Monica escapes. As Jonah is transferred to a surgery, Lopez lures a disguised Monica to another patient's room before arresting her. Wesley decides to take on a higher position at the DA's office following advice from his mother. Grey surprises his wife with horse lessons, but later informs Nolan that he will be transferred to a new station due to Nolan angering the union president, forcing him to miss his TO exam.

Nolan and Bailey travel to the border town of Frontera, where he is to spend his "day in the hole" with local cop trainee Gabrielle Navar. Their calls are limited, and Nolan assesses that she is doing good, until a roadside pull-over almost leads to a shootout. He notes that she didn't evaluate the risks properly. The man they arrest, Blair Darvill, asks them to let him go before his gang gets suspicious, but Nolan refuses. Its leader arrives and tries to bribe Nolan, but when he refuses, the gang shoots up the station-diner in an attempt to retrieve Blair. With a combined effort with Gabrielle and Ellroy, Nell's boyfriend, they defeat the gang and have the survivors arrested as the CHP arrives to assist. In Los Angeles, Lucy investigates the discovery of drugs in Tamara's new car, which turns out to belong to Jake Butler, a doppelganger of Tim. Reluctantly, he agrees to go in undercover to Jake's boss, Roy Hajek, who gives him another mission. Lucy is surprised to discover that Jake's girlfriend is a doppelganger of herself, and is tasked to work with Tim undercover, although they struggle to make an authentic backstory for the two and unexpectedly kiss. Harper approaches Grey and asks to stay on as a detective after her maternal leave, which he accepts and arranges for Aaron to receive a new training officer.

As a reward for his heroic stand down at the border, Nolan is offered a "Golden Ticket", his choice of assignment in the LAPD. His fellow officers (and Bailey) all have suggestions for him but the chief urges him to think it over before deciding. While Tim and Lucy continue their undercover assignment with Roy's crew, Nolan and Grey assist with securing the courthouse for the trial of Rosalind Dyer. With the help of her attorney, Rosalind escapes. Grey gathers the loved ones of his officers at the station for protection while he, Nolan and Harper help with the manhunt. Tim and Lucy learn of the escape while en route to Las Vegas but Lucy insists on continuing with the assignment. They rendezvous with Lopez and Aaron at a casino and make a plan to take down Roy's crew and their employer but their cover is blown by an ex of Tim's doppelganger, Jake. Fortunately, Lucy manages to subdue and arrest the crew. Nolan decides that he wants to become a training officer. Rosalind is able to escape LA after robbing and murdering her attorney's parents and then slitting Chris' wrists and leaving him for dead in Lucy's apartment, where she and Tim find him before they can confront their feelings for each other.

Chris recovers from his injuries. Lucy is offered to go to undercover school, but is hesitant despite encouragement from those closest to her. Nolan passes his TO exam and is scheduled to attend a certification course, and Grey allows him to be Aaron's TO as a trial run. The two respond to a welfare check and discover the corpse of a deputy sheriff. The ensuing investigation reveals that the deputy and a group of his colleagues worked undercover against drug dealers, but instead took the cash from the ones they were meant to arrest. The deputy who died left recordings of his interactions with his colleagues, which proves their corruption. Harper is in maternity leave and is due to give birth, but becomes suspicious of her and James' neighbors. Once gun shots are heard, Smitty arrives and investigates, but doesn't find any evidence of her claims. Harper later sees the neighbors putting a corpse in a car trunk and reports her suspicions to Grey. The night she is due to give birth, the neighbors break into her house and one of them attacks James just as Grey arrives. Harper manages to tackle the second man on her own and gives birth to a baby girl. Due to the deputy investigation, Nolan expresses that he didn't feel he taught Aaron much, but he assures Nolan that his tactic was beneficial.

One month later, Nolan has finished his TO certification, Lucy has finished her undercover course and Harper has returned to work. Nolan is assigned rookie Celina Juarez, and the two come off to a rocky start after a traffic stop gone awry. The vehicle is revealed to contain a blood stained carpet, but since the evidence was obtained illegally, it can't hold up in court. The carpet is also revealed to be linked to the disappearance of Jill Baskin, whose case Harper has taken on. Together with Lopez and Harper, Nolan and Celina work undercover to follow Jill's suspected abductor Tyler Harvin, but he escapes. While looking through evidence, Celina has a dream about where Jill could possibly be held. Nolan decides to give her a chance after refreshing their working relationship, and the two search a property in the woods, where they find Jill. Celina pursues Tyler and ends up in a fight with him before Nolan locates her and arrests Tyler. Lucy patrols solo and is locked inside an old warehouse while conducting a welfare check. She has an epiphany after looking through a document from the Dye Hards, an online group Chris joined looking into Rosalind Dyer. After Tim and Aaron finds her, she and Chris approach the FBI with the suspicion of Rosalind being a user in the group, which they track to an address in Seattle. Lucy joins the team to the city and find a blood written message from Rosalind on a wall at the address, saying "Better luck next time".

• Britt Robertson (Laura Stensen) and Felix Solis (Matt Garza) are credited as Special Guest Stars.

While responding to a supposed medical emergency, Bailey falls into a booby trap in the floor of an old house. Her entrapment leads to a more challenging rescue mission for the fire and police departments, all the while Nolan receives a call from Rosalind. She asks him to come and meet her one last time, and if he tries anything, Bailey will get hurt. The rescue team discover obstacles at every turn in order to rescue Bailey, and the tank begins to fill up with water. Nolan leaves clues for his colleagues, but his trail ends after he is asked to drive a van to Rosalind's location. Harper, Lopez and Aaron, together with Laura Stensen and Brendon Acres from the LA FBI office, investigate a warehouse where an acolyte of Rosalind, Jeffrey Boyle, has stored materials for building booby traps for her victims. The former three spot Jeffrey and chase him, but he triggers explosives which detonate the warehouse. Luckily all of them make it out in time. With notes of how the traps work, the rescue team manage to disarm other traps while activating a last one before Bailey is finally recovered from the tank. Nolan arrives at Rosalind's meet up location and the two have a last supper before he is meant to kill her. But living up to his moral, Nolan doesn't kill her and decides to bring her in. However, as he calls it in, a sniper shoots and kills Rosalind.

---

This episode begins a crossover event that concludes on The Rookie: Feds season 1 episode 4. Britt Robertson (Laura Stenson) and Kevin Zegers (Brendon Acres) are credited as Special Guest Stars. This episode also marks the final appearance of Rosalind Dyer and the last appearance of (Annie Wersching) who died from cancer on January 29, 2023, at the age of 45.

Lopez finds her mother at the door, who explains that she was attacked by someone claiming that one of her sons should be cautious. Harper takes the case, and Lopez calls in all of her brothers all but one who is studying in New York. Neither of them admits to having any knowledge to their mother's assailant, but Lopez later learns that one of them, Damian, cheated with the wife of a former gang member working at his church. She and Harper also discovers that another one of her brothers, Benny, was in debt after putting money into the stock exchange and a loan shark came after him. They head out and arrest the loan shark for attacking Lopez's mother. Nolan and Celina respond to a car accident, but the driver escapes from the ambulance upon arriving at the hospital. The driver, revealed to be Rob Lukasey, burgled a house and was shot by a man in self defense. The hospital is put on lockdown as Rob tries to find a way to heal himself. He disguises himself as a medical officer and then a doctor before taking Celina hostage. She however manages to subdue him with morphine under the guise of treating his injuries. While helping at the hospital, Tim is hospitalized with after effects of a previous bullet wound. He has a surgery and successfully recovers, but his girlfriend Ashley breaks up with him. Grey is also hospitalized with food poisoning after eating at a restaurant with colleagues, leaving Smitty and Lucy in charge of the station with Lucy managing to successfully keep everything running despite the station being down on half of its personnel.

Nolan and Celina respond to a money dispute at a bank, which is later revealed to have been burned following a robbery. Celina herself suspects that the money is cursed after the woman, Macy Tompkins, they met at the bank, is found dead at a luxury flat. This is after Harper and Lopez launch an investigation in cooperation with the DEA after it's revealed that the money once belonged to drug smuggler Winslow Harris. Celina has another dream where she gathers that Winslow would depart by boat, which the DEA agent confirms from his older cases. Together with Nolan and Celina, they apprehend Winslow at the marina, who also explains that he killed the agent's partner by accident. While helping a movie director with some props, Tim loses his radio. The director returns it to Lucy, who puts Tim and Aaron out on a hunt for it. She eventually returns it, hoping it would help him move on from the breakup with Ashley. Wesley and Sean Del Monte proceed with the case against Elijah Stone, and Wesley is surprised to learn that his ex-girlfriend Monica is Elijah's defense attorney. She tries to portray both Wesley and the LAPD as incompetent and goes out of her way to make the case personal for Wesley. Despite his warnings to her that Elijah is manipulative, she also blackmails Del Monte into dropping the case. Elijah later meets Wesley outside the office and warns that he hasn't seen the last of him yet.

Elijah launches a lawsuit against the LAPD, specifically targeting Wesley, Lopez, Nolan, Grey and Harper for their participation in freeing Lopez from La Fiera. He also files a restraining order against Wesley and orders him to publicly apologize in front of a press corps. Nolan and Celina investigate the murder of doctor Alvin Mitchelsen, who was already dead when he was shot by a former patient. Initially they discover that he was stabbed, but medical examination further adds that he was poisoned. His former patient reveals that she shot Alvin due to his mistreatment of her father's drugs, while his wife reveals he had heart problems before his death. Nolan and Celina deduce this as a cover-up of her actually having killed him with poisoning. Aaron connects with a young boy, Tabin Cordon, after he and Tim respond to a noise complaint, but Tabin is later revealed to be the brother of Vina Cordon, a member of the female gang Double R led by Shana Quelli, who Harper, Lopez and Lucy are investigating for a murder. Lucy goes in undercover and makes connections with Shana, while Tabin is temporarily reunited with his sister. During debt collecting, Shana alludes to Vina having murdered the victim Harper and Lopez were investigating, and Vina is later arrested at her family's doorstep.

Aaron gets to tag along with Harper and Lopez as a part of following his desire to become a detective. The two gives him an old case to solve and limits him to ask them five questions. Nolan and Celina attempt to stop a speeding driver, Pam Winfield, but she is revealed to have a collar around her neck. The police guide Pam to a secure spot and the bomb squad attempts to rid her of the collar, but the bomb goes off after she tries to open her door, killing her. Tim and Lucy discover another driver, Creighton Mitchell, also with a collar around his neck. However, he panics, grabs some garden shears, and manages to get the collar off. He later identifies the assailant as Richard Dormer, a colleague at an oil company they both work for. He also reveals Richard's motives stems from his sister Susan dying in captivity abroad and the company unsuccessfully negotiated her release. Nolan, Celina, Harper, Lopez and Aaron arrest Richard at his home without resistance. His last target is the company CEO Henry Parsons, who he wants to livestream an apology. The police evacuate the company building and Nolan works to disarm Henry's collar. Henry delivers an apology, but Celina deduces that Richard wants to see him dead despite the apology; and instructs Nolan to cut the collar's red cable, disarming the bomb. Chris proposes house hunting to Lucy, which takes her aback and she struggles with keeping up with him and sorting out her feelings for Tim.

Grey and his wife visit their daughter Dominique in New York but become concerned when she does not meet them and contact the NYPD, who advise that it is too soon to worry. The couple investigate and learn from her room-mate that Dominique has made some possibly dubious new friends. They trace her movements, which lead to a Uber driver who appears helpful but Grey spots his taxi has a broken tail-light, a trick he taught Dominique. They follow him and rescue her from her abductors. Celina fights and apprehends a jewelry store robber, Ryan Davis. Placed in a cell, he is injured in a fight with other prisoners. He later dies in hospital of a ruptured spleen. There is an investigation to determine whether Celina or the prisoners caused his death. Nolan supports her as her union rep during questioning by Wesley and Chris. An autopsy and camera footage proves her innocence. Lucy agonizes and rehearses scenarios with Aaron for her break-up but when the time comes blurts out Tim’s blunt advice and asks Chris to “hand in his playbook”. Nolan assists Tim’s sister, Genny, to recover her lucky-charm bracelet, thrown away by her son Tyler, furious at her divorce. Lucy breaks up with Chris and starts a relationship with Tim.

Tim and Lucy go out on their first date, but find themselves tackling a dispute between a cook and chef. Grey warns them against a relationship, and has them separated on duty. While taking out money at a bank, Harper and James find themselves in a middle of a robbery committed by serial robber Todd Shelf and three associates. Harper has an employee trigger the silent alarm and the police arrive. Todd and Roger Armistead escape, but Todd leaves him behind. The FBI are called in, and the LAPD works with Simone Clark (Niecy Nash) and her superior/training FBI Special Agent Carter Hope (James Lesure). They track an unusual money wiring to Taylor Barnes, who reveals he hacked the FBI's undercover agents and informant list to sell to the highest bidder. Taylor is shot by a sniper before he can reveal the buyer's identity. Tim and Lucy and their reinforcements surround Roger taking a hostage in a neighborhood. Bradford hatches a plan to distract him and Roger is subsequently arrested. At a hospital, Todd's third associate, Amy Wright, escapes and reunites with Todd. They push Tim and Aaron's patrol car off a parking garage roof, but the two narrowly escape. Shortly after, Nolan and Celina finds Todd dead in the truck he and Amy stole.

---

This episode begins a crossover event that concludes on The Rookie: Feds season 1 episode 10. Nancy Nash-Betts (Simone Clarke) and James Lesure (Carter Hope) are credited as Special Guest Stars.

Lopez is approached by her brother Damian, who asks her to look for a kid gone missing from his local shelter. She and Harper take the case, and learns that the kid, Matteo, was involved with the gang run by Quinlan Wright. They meet with Nolan and Celina and search an abandoned building were Matteo's phone last pinged. In a walk, they discover his body packed liked a cocoon along with other bodies. Harper and Lopez question Moses Warden, Quinlan's rival who denies any wrongdoing. Just then, Quinlan's men arrive and shoot up the workshop. Facing contradicting information, Lopez and Harper has Damian bring in the gang's informant Ricky, who reveals that Elijah Stone told him to inform the police about a drug bust. With this in mind, they conclude that Elijah orchestrated a gang war in order to clear his name. Lucy is tasked with hosting the Citizen Academy at the station. She suspects one of the attendees, Kyra Cook, is facing domestic abuse after she raises a question about it. She convinces her to go to a shelter, but she leaves it after an incident with staff. Kyra calls her again when she again faces abuse from her boyfriend Oliver. Lucy arrives at their house and fights Oliver and arrests him before Kyra holds her at gunpoint. Lucy manages to talk her down before arresting her as well. Tim also acts as a baseball coach for his sister's son, and gets help from Lucy.

Oscar Hutchinson has prison leave to donate a kidney to his estranged daughter, but Nolan and Celina have their hands full trying to protect the ever-manipulative Oscar – whom makes constant attempts to delay the procedure so he can stay out of prison longer – from attempts on his life by past victims of his crimes. Lopez has a tense exchange with Harper while investigating one of Elijah's associates before apologizing and admitting the stress of her unexpected pregnancy weighing on her. Tim and Lucy continue struggle to keep their budding romance from interfering with their work, especially when they're assigned to ride together for a single day, until a transfer opportunity arises for each. Ultimately Tim decides to ask for a transfer. Nolan, Celina, Tim, and Lucy end a plot to block Oscar's surgeon from performing his surgery.

A heat wave is causing rolling blackouts across the city, but the precinct has a backup generator. Nolan's trainee Celina misses a question from Sgt. Grey, causing him to be her partner for the day. They foil a robbery in progress, and Grey puts her on command post duty. She is overwhelmed, but the assignment was meant to teach her to ask for help, which she does when she can't get in contact with her mother. When the backup generator at the station fails to come on, Nolan and Aaron discover two people pretending to be cops to try and break a friend out of jail. They rat on a ghost gun seller who Lopez takes down in an undercover operation. The gun seller rolls on a fentanyl dealer processing raw product in a home. Surveillance shows there to be a child in the building. Celina is exposed while rescuing her, but resuscitated by a dose of Narcan. Lucy sets dominoes in motion to get Tim transferred to Metro, back on the street where he belongs. Celina carefully checks in with her mother from the hospital, who thinks she only does desk duty. A side story has most of the cast spending time at Nolan's, who installed a backup generator and has air conditioning.

Tim starts work with Metro and experiences some initial setbacks during training, but eventually proves himself and is welcomed to his team. Bailey is in an ambulance that gets shot at, the start of a rage killing spree of firefighters and EMT workers. Nolan finds the perpetrator and arrests a fired firefighter. Wesley loses a routine preliminary decision related to Elijah, which makes him suspect that the judge working the case, Rivas, is on the take. He confronts Judge Rivas, who hints at the truth and then dies mysteriously of a heart attack. Wesley warns Monica that Elijah could be targeting her next. Tamara is working multiple jobs to try and move out of Lucy's place to give Lucy and Tim privacy. The parents at her babysitting gig act strangely, leading to the police investigating the mother's kidnapping due to the father's illegal activity. Tim participates in the rescue as part of Metro. Over the course of his day, Nolan receives calls from his mother, who wants to be paid for staying away from his wedding. He looks away from her "tricks", assuming that a doctor calling him is a fake sent by her, until finally learning that she died in the hospital.

With help from Matthew Garza's team at the FBI, Lopez puts everything on the line to help Elijah Stone take down Abril Rodas in exchange for her safety as part of an elaborate operation. Garza's team moves to utilize Abril's girlfriend Daylin as bait for Elijah. But the night he arrives to execute her, he withdraws at the last minute due to a unintended distraction caused by Aaron. Unbeknown to both the LAPD and FBI, Elijah approaches Abril and offers to work with her. Nolan and Bailey travel to Nolan's mother's now-vacant home in Foxburg, Pennsylvania, and must deal with the secrets and shady dealings his late mother left behind including someone masquerading as Nolan, drug dealers, and a foreclosed mortgage.

• Britt Robertson (Laura Stenson), Felix Solis (Matthew Garza) and Kevin Zegers (Brendon Acres) are credited as Special Guest Stars.

The Mid-Wilshire station works with Victorville PD detective Noah Foster to stop a militia group from using sarin gas in a terrorist attack in the city. When a member of the militia turns up dead due to the gas, they bring in his sister for more info, but she plays dumb. However, a tap on her phone reveals that the group is targeting Union Station. A road block with spike strips is set up while Aaron and Harper force the truck with sarin gas towards it. Blocking the truck in, they order the driver out and arrest him. Bailey, Celina and Harper work with the CDC to secure and quarantine three men returning from Nigeria who are suspected to be exposed to Ebola. Though all of them cooperate, the third forces an entire bus into quarantine due to potential exposure. Lucy detects animosity from Tim, which she learns is due to him learning that she was behind his transfer to Metro. She convinces him that it was the best move, despite not informing him beforehand. Lopez and Wesley increase their residential security by hiring a private security specialist. They receive a Valentine's Day "gift" from Elijah Stone – dead roses crawling with insects.

Elijah begins to question Monica's loyalty, but is convinced after she forms a plan to double play the LAPD on his trail. She approaches them under the guise of finally helping, but Grey and Harper quickly deduce her play. The second time Monica reports on Elijah's moves, the police manage to decode the real location at the Port of Los Angeles. A shootout ensues and Elijah subdues Harper, but Lopez wounds him and she and Harper arrest him. After Harper allows her to leave, Monica secretly contacts Abril and offers her assistance. Nolan re-opens Celina's sister Blanca case and with Celina discovers a new lead which fractures their mother's previous alibi. Nolan learns from a witness that Celina's mother that they were taking opioids together while Blanca and Celina were left home alone, during which Blanca disappeared. Her mother is eventually brought in for questioning, and admits the truth to Celina.

---

This episode begins a crossover event that concludes on The Rookie: Feds season 1 episode 17.

Tim's look-alike Jake Butler is out of prison, so he and his girlfriend Sava go on a new crime spree. Their plan is to take jobs such as handyman or nanny for a rich and/or famous family, then steal from the family. After an initial score on Lance Bass, they move on to the Boudelaire family with a stash of very expensive and often illegal antiquities in a secret room. Jake goes missing and is later found dead, while the family's nanny is also found dead in their garden house. Mid-Wilshire question one of their previous handymen, who admits that had accidentally killed the nanny. Sava receives threats from Turkish dealer, who the CIA had connected with an Iranian weapons deal. A video from Jake and Sava's stolen car leads the police to her friend Lisa Miller, who Jake had an affair with and took a historic gun from the Boudelaires and killed him. Nolan is shot during her arrest, but survived thanks to his bullet-proof vest. The story is told as an in-work documentary, with character interviews interspersing the action.

Celina visits her sister Blanca's grave on the anniversary of her abduction. Lopez finds that the abduction fits a pattern of cases dating back years before, all of the abductions happening on the same day of the year and all the victims being from drug-addicted parents. Then Nolan and Celina get a call about a missing girl, starting the cycle over again. An older officer, Joel Chambers, shows up at the scene who Celina recognizes from her case, and he makes Nolan suspicious by asking to enter the scene. Grey asks an old investigator about anything that didn't make it into Blanca's kidnapping, which leads the team to a serial sex offender suspected, but unable to be tied to the case. Harper asks Joel about details in the Juarez case, and he's caught in a lie, raising suspicions higher. They release him with Tim following him, but he uses his police skills to flee. Lucy finds a recent case Joel worked on where he cleared a house of squatters just a couple miles from the abduction. The team surrounds the house and talks Joel into letting the girl go, but when the team moves in, Joel raises his gun against Tim, who is forced to shoot him. Lucy offers to help Tim get through the experience, and he offers to help her study for her detective exam.

Tim's ex Isabel approaches him, asking for assistance in finding a missing girl, Dara Teska, whom she looked after during a past assignment. Together with Lucy, they determine that Dara fled home and went into hiding in a motel Isabel used to bring her to for safety. Upon securing Dara, Isabel and Lucy are forced to reveal their real identities in order to help her escape hitman sent by her uncle Ed to also kill her father. After securing her, they learn that her father had her uncle killed, and Isabel promises to stay in touch. Grey assigns Aaron to assist Lopez during her day due to her second pregnancy, but he ultimately asks her to stay at home until the baby is born. Harper and Nolan assist Skip Tracer Randy when he stumbles upon a dead body after breaking in. The victim had a prior history of trolling people online, which Randy had been asked to investigate. His constant interference with their investigation, forces them to take him along, but holding him at bay. Randy deduces that a friend of his with prior history has been cryptically threatening him through emojis, and he decides to row him up in order for Nolan and Harper to arrest him. Meanwhile, Bailey's friend from college, Libby, is crashing with them and is dragging her around L.A. in an attempt to relive their college days and avoid her own problems, culminating in a meet-up with an untrustworthy man that leads to Bailey's arrest when she gets into a fight with the man and then runs away. When all is said and done, Libby decides to return home, but not before accusing Bailey of being an alcoholic, both to continue avoiding her problems and to avoid taking responsibility for her recent actions.

Lucy goes undercover as a sales agent in order to gain Frank Teska's interest following his release from prison. Once he approaches her, he asks her to take some under payment in favor for products from her company. Frank learns that his brother's crew is after him, while some of his own men has also turned on him. After a drive-by shooting, he determines a close associate was behind it, but Lucy stops Frank from killing him as Tim and the police descend on their location. Frank concedes that he has lost control over his crew after his prison time and wishes to reconcile with his daughter, which Lucy encourages him to do. Aaron assists Lopez with detective work while she is at home, and questions a reluctant witness of a robbery, which leads to a vehicle with a dead body and workshop with a decreased suspect. He manages to solve the case in addition to seven other tie-ins. Harper, Nolan and Celina tackle a cold case favor which involves a severed torso. A broad search recovers an arm belonging to it and two friends of the victim. Video footage in their possession reveals that they accidentally shot their friend with a machine gun while recording a video, cutting up his body and hiding the parts.

---

This episode begins a crossover event that concludes on The Rookie: Feds season 1 episode 21.

Aaron and Celina are ambushed by masked assailants after investigating a suspected disturbance, and are seriously wounded. When hospitalized, Celina recounts a riddle to Nolan said to her by one of the assailants. Mid-Wilshire is put on high alert, and even further when Nolan and Bailey are attacked and Harper's child is temporarily abducted. Lopez works with Wesley and Luna Grey in deducing the riddle. The police look into past run-ins, identifying one with a prior record and finding him dead in his boobytrapped house. They further narrow his possible prison encounters, with Tim and Lucy visiting Luke Moran. An army of masked men with police shields pursue them, but they're swiftly taken out with reinforcements on-scene. With Luke caught and surrounded, he chooses to try to fight back before being shot down. As further reinforcements roll in, an unknown man in a passing vehicle praises how well Luke served as a distraction.

Following Luke Moran's death, the Mid-Wilshire officers learn that his attack was a diversion for a professional crew to rob the Federal Reserve Bank. Nolan and the others arrive at the bank and a shootout ensues, forcing the criminals to sacrifice three of their own to stall for time to escape. Six weeks later, one of the surviving thieves is hospitalized following a car crash and is killed while attempting to murder a nurse. A search of his rental house turns up a phone which leads them to the remaining crew, all of whom are arrested after a shootout at the airport. Lucy is studying for her detective exam and asks Tim to challenge her with outside the box tests. She makes a mistake that compromises evidence in a murder. Her self-doubt causes her to question Tim's motives. Aaron returns to duty following his shooting and is assigned to desk duty until the department psychiatrist, Dr. Blair London, signs off on him. Boyd, the leader of the crew, takes a deal with defense attorney Monica Stevens following his interrogation but is killed by a sniper while en route to jail.

Nolan and Bailey's wedding day is just one day away, but first must contend with a seemingly endless stream of disasters, including a lawsuit against Nolan by Oscar Hutchinson. Skip Tracer Randy accidentally pawns Bailey's ring, and Tim and Lucy go to retrieve it from a known criminal called "The Hammer", who has a penchant for fighting. The two also take time to address their own fight over Lucy becoming an undercover detective, which Tim discovers he has more reservations over than he thought. Celina and Harper discover a heroin smuggling ring disguised as a pottery dealer and Celina uses it to try and land her first case. Grey ends up officiating when the minister gets stuck in traffic and the ceremony goes off well, with Randy filling in as DJ. Tim and Lucy agree to work through their issues, but Aaron is gently rebuffed when he tries to kiss Celina and gets drunk as a result. Celina goes to meet an informant and is kidnapped leading the rest of the team to come to her rescue.

Nolan and Bailey's secluded getaway honeymoon turns into an active crime scene when their housekeeper washes up dead on the beach. They suspect a bandaged loner also staying at the resort of being the killer and all efforts to escape and get help prove fruitless before they are abducted. Harper and Lopez join them as backup and use footage from Nolan's cameras to track them down, arriving just as he escapes and subdues the suspect. Celina is assigned to Tim in Nolan’s absence while she also struggling with Aaron's kiss, and he struggles with his own feelings. Lucy continues to prepare for the detectives' exam and Tim cautions her about overpreparing. They and Celina soon get caught up trying to identify an amnesiac shoplifter. Lucy takes her detectives' exam, while Tim and Celina follow a lead and find the shoplifter's partner stuck in a wall, having got stuck during an attempted heist. Aaron and Celina mend their friendship and Lucy passes her exam but ranks low. Nolan and Bailey salvage their honeymoon by having a relaxing staycation back at home.

Aaron is cleared to return to duty and undergoes tests with Tim to see if he can still overcome the workload. Aaron decides to be more thorough in the case they are given but is frustrated when it comes to an unexpected end, with the husband of a woman supplying a criminal with money, ends up dead in prison. Furthermore, the wife is revealed to have ordered his death due to his history of abuse. Nolan and Celina respond to a dead body discovery, which they soon learn could be another victim of the long-lost Pentagram killer. The case takes a turn when they learn that the victim was disliked at her school, and a man escapes after witnessing his wife being killed at his home. The victim's brother is revealed to be responsible when he shoots up the recovery scene, and Lucy is injured. Despite this she faces the brother solo, who she later learns survived his injuries, meaning that she will potentially be witnessing against him.

Tim calls off a date night with Lucy, to meet a former army friend, Mark Greer, to discuss plans to eliminate Ray Watkins, who once betrayed them in the past. But he finds himself unable to go through with the mission after confronting Ray, deciding to take all the heat if Ray ever strikes back, with Mark ditching the plan shortly after. Nolan and Celina respond to a murder of a family, with only a mother and her toddler daughter surviving. However, the mother later dies in hospital and Nolan suggests he and Bailey could take care of the toddler until either relatives or a foster family is found. Bailey worries about taking care of the toddler due to past trauma looking after a neighbor's child. Harper and Lopez lead the investigation into the family's death and learn from their tenant that a coworker of the father became vengeful over a lottery ticket. A shootout ensues at the coworker's residence before a swift arrest. Meanwhile, Aaron encounters Blair at a bar, and she takes an apparent liking to him, but later denies it at a meeting. Nolan and Bailey decide to adopt the family's toddler, but are disappointed when her uncle arrives to take care of her instead.

Lopez inquiries into the nature of Tim's secrecy after learning about Lucy's worries. Eventually Tim comes clean to them after Ray visits Lucy's home. The trio determine that he is a gun for hire just as he abducts a Venezuelan activist, which they manage to stop, and an IA investigation is launched. The investigation, during which Tim lies to Percy West, the late Jackson West's father, clears him of any wrongdoing against Ray, but internal ramifications await. Additionally, Tim decides to break up with Lucy. Nolan and Celina track an escaped inmate from a community event, learning that she sought retaliation against whoever cheated with her boyfriend, surprisingly revealed to be her own mother. A bag from the same event leads Harper and Aaron to reopen the investigation into Karina Lewis' murder, which they gradually determine had a false confession and murder weapon. After pinpointing the gun's make, model, residue and owner, district attorney Del Monte reverses the original verdict in favor of the new evidence. Bailey is more determined to have a baby, but Nolan is hesitant, citing his old age and work schedule, but eventually decides in favor of having another baby.

Tim is demoted and placed back on patrol. He also receives a psychological evaluation from Blair, who concludes that he still is fit for duty. Meanwhile, Nolan and Celina track down a man who had an affair with his babysitter. They and the others later learn that the babysitter's friend also was kidnapped alongside her, but later find her dead in a parking garage. The babysitter later manages to escape, and they find the man dead in his car. En route to the hospital, the babysitter escapes and wields a knife at police. She reveals that she is pregnant and had killed the man when he broke things off and her friend when she wanted to call the police about the murder. Tim decides to go to therapy despite Blair's positive conclusion. As Tamara moves out, Celina asks Lucy if she can become her new roommate, which she accepts. Harper and Lopez share babysitter advice and vet a new babysitter, which they ultimately decide to share, with her taking care of both of their children when required.

Tim and Aaron are placed on watch duty for a Metro SWAT raid. Meanwhile, the LAPD has to handle a massive gang war between the Eastern Front and a rival gang that finds its way to the hospital. After repeatedly intervening to help, Nolan and Bailey eventually get to their doctor's appointment and learn that she can't bear children. Although IVF is suggested as a solution, Bailey decides against it. The SWAT raid is compromised and an officer is left paralyzed. Tim suspects "Mad Dog", a member of his Metro team, is a mole and confronts him on a rooftop. Mad Dog confesses to his suspicions and commits suicide, but not before giving Tim a tiny hint. Celina moves in with Lucy, and shortly afterwards receives a birthday card from Tim. Monica Stevens is assaulted by a professional hitman in her home. The hitman is killed by Monica in the hospital, and it is also implied that Monica is working with Blair and Mad Dog. Meanwhile, Harper and Lopez both suspect Monica in the hitman's death, which they currently cannot prove.

IA investigates the suspicious circumstances surrounding Mad Dog's death, but Tim finds himself being tainted by the IA investigator Pearson, who it is implied has a vendetta against him and is later revealed to be working for Blair. Nolan and Celina secretly investigate Blair and later turn to Smitty, asking him to keep an eye on her comings and goings and her patients. Monica investigates who might be looking to kill her, which leads her to the city's money laundering top criminal, Christian Batista. Concurrently, Lucy goes undercover as a new babysitter at the Batista home after Harper and Lopez learn that their babysitter formerly worked for him, and his enforcer shows up at Lopez's home. Nolan confronts Blair with evidence from Mad Dog's flat that implicates her, and she eventually agrees to testify in exchange for immunity. A lead from a computer search leads Grey, Harper and Lopez to proof that Pearson was in on the conspiracy. Monica tracks down her attackers and learns that they were hired by Eric Ramsey. In exchange for assistance against Ramsey, she agrees to help Oscar Hutchinson escape prison.

Nolan and Harper team up with Matt Garza and his FBI team to uncover the conspiracy. Meanwhile, Monica's hit crew starts killing any witnesses against her, which includes Pearson, before later capturing Blair. Monica's crew attempts to kill the hired gun Gundo after he double-crosses them, but is thwarted by Tim, Lucy, and Lopez. Monica makes plans of her own for revenge against Ramsey, in which, after confronting him, she resorts to blackmail against him over an affair he had with the wife of Swiss businessman Jakob Olmstead. She takes Blair to Argentina, and it is revealed that Blair escaped hit and run charges with Monica's help, and plans to reel Jakob over to her side against Ramsey. Nolan and Harper rescue Blair in Argentina through a black op with the assistance of the CIA and FBI, but Nolan is shot in the hip during the rescue, which allows Monica to escape. Garza ensures that an Interpol warrant is placed on Monica. Tim apologizes to Lucy, lets her know he will always hold her kindness and repay as much as he can. Oscar and Jason Wyler, Bailey's psychologically abusive ex-husband, break out of prison. Sergeant Grey contacts Nolan while he and Bailey are talking about adoption, letting them know that Oscar and Jason have escaped.