Following violent, targeted attacks on 15 Division, the officers must piece together a past crime in order to find Oliver; the shooter's plan is revealed.

When Andy and Chloe respond to a routine 911 call, they are blindsided by an unseen shooter out for revenge.

Andy's world explodes by a seemingly senseless act of violence during a concert shooting. When she sets out to unravel the details, she comes into direct conflict with Luke's former partner, Detective Jo Rosati, a new detective with Division 15. As Rosati investigates the case, sparks soon fly between her and Luke.

When Dov and Chris discover a missing girl's body in a ravine, Detective Luke Callaghan returns to oversee the investigation; when the officers learn that Gail has been abducted, they rally to track down her captor.

Detectives Callahan and Rosati are at odds over how to correlate and interpret the facts of two vicious crimes. Luke feels strongly that the latest woman attacked on her watch is connected to an unsolved rookie's murder, but his erratic behavior gets him kicked off the case. Andy may be in serious trouble when Luke urges her to follow through with his hunch on the crimes.

Blaming herself for Swarek’s mysterious disappearance and fearing for his life, Andy struggles to find a lead in the case. Will Andy and the other rookies find him in time? Little do they know that shocking events triggered by this investigation will incriminate one of their own and may also put an end to Andy’s career.

Strange happenings and a full moon rattle the rookies. Andy and Sam investigate the theft of some severed heads from a medical lab. A particular man catches their attention as a suspect with his obsessive behavior. While trying to protect a young woman who could be the next target, Andy puts her life and Luke's in jeopardy.

Andy and Chris accidentally screw up one of the biggest drug busts of the decade when they arrest one of the players. In an effort to save the operation, Swarek and Andy go undercover to make the drug buy. When Andy realizes that their bait and switch has created an ambush that will endanger Swarek’s life, it’s all hands on deck as the coppers of 15 Division rush to save the life of one of their own.

With the 15 Division restructuring looming, Andy and Sam’s wedding comes just in time for the gang to celebrate one last hurrah. But when Andy is taken off-course by a hitchhiker and then stranded on the side of a dead-end road with a dying man, she finds herself with no way to get help – or let Sam know she hasn’t bailed. Will she save the man’s life? Will she make it to her wedding?

When Gail’s uniform is stolen from her car, she and the other rookies from Division 15 attempt to catch a cop-impersonating vigilante. A drug deal gone awry may offer clues to help Chris and Dov unravel the motive behind the cop masquerade. Meanwhile, Andy and Sam’s inability to stay away from each other poses a life-threatening risk to Swarek.

The officers of 15 Division work to track down Ted McDonald. But even after catching him, they realize Ted has more targets set to explode out there. The clock is ticking…

The officers try to prevent dangerous fallout when a laptop containing sensitive information is stolen; a wedge is driven between Sam and Andy.

A violent pedophile escapes during an emergency hospital visit and abducts a girl; Andy faces a serious decision; Chris considers a transfer.

After a routine speed trap leads to a messy accident on a city highway, Chris and Gail find one of the cars mysteriously empty and quickly realize that its license plate matches the one being broadcast in a citywide “Amber Alert” – a nine-year old girl has been abducted and the driver of the vehicle is the prime suspect. A whirlwind manhunt ensues involving a complex interrogation of the missing child’s parents. As always, everyone has a secret.

While working a kidnapping case, Andy and Swarek find themselves on the scene of a car accident. As Swarek and the rest of Division 15 pursue the kidnapper and missing child, Andy remains at the scene with a woman trapped in her car. A transgression involving Gail puts Chris at odds with Dov. Andy concludes that it's time to re-evaluate her life.

It's a race against the clock as Dov and Gail work under Swarek's expert tutelage in a stakeout operation to stop an Asian gang from killing a snitch. Meanwhile, at Mounted Unit training day, Andy and Chris join the rookies from Division 27 in a competitive equine training event that gets Andy back in the saddle - both personally and professionally.

Andy and Gail go undercover as cocktail waitresses to clean up a drug-infested club, but get more than they bargained for when their fellow waitress turns out to be involved with a vicious criminal. Meanwhile, Traci wrestles with feelings for her old flame, Detective Barber, Dov tries to weather the storm when a young woman files a complaint against him, and Andy unwittingly opens up to Sam about her commitment to Luke.

Nick and Andy go missing while working under cover to infiltrate a meth pipeline; Swarek and the other officers find themselves in the middle of a rescue operation; Andy works to deal with all the change going on around her.

When Dov walks into a robbery in progress and shoots a black teen, the community calls for him to be investigated.

A severe heat wave wreaks havoc on the city, forcing the rookies to work around the clock to keep the peace. In the midst of the chaos, Andy discovers that a serial rapist may have resurfaced to prey on vulnerable teenage girls. And when the extreme temperature precipitates a citywide blackout, Andy finds she’s cut off from all backup and must take.

When an arrest reveals that drugs contaminated with a deadly bacteria have hit the street, the squad rushes to control the situation; Marlo reveals a shocking secret; Dov suspects Chloe of hiding secrets.

In the aftermath of the night's traumatic events, Andy and Dov try to pull themselves together at an all-night diner, but are caught off-duty and off-guard in a volatile diner hold-up. Meanwhile, the weary officers at 15 Division struggle to contain the evening's collateral damage under the watchful eye of a tough new Inspector.

While working on a high-stakes gun raid, Andy and Gail stumble upon a victim of domestic abuse whose brutal experience in the system has taught her not to trust the police. When Andy promises to protect the woman from her abuser, she soon learns that it takes more than just following protocol to be good at her job. Meanwhile, the other rookies get caught up in the annual police retirement boxing match – a fundraising event known as “Fite Nite.”

As the officers of 15 Division try to move on from the corruption scandal, a heat wave hits and Jarvis opens the division to the public as a cooling station. Andy heads out with a very-pregnant Marlo to find a volatile woman who’s gone missing after group therapy, but neither Andy nor Marlo are prepared when Marlo suddenly goes into labor.

A riot breaks out at a women’s correctional institute while Andy, Juliet, Nick, and Gail are there to transfer prisoners. They end up separated and in a lock-down situation that finds Andy and Juliet trapped with a woman desperate to prove her innocence.

Andy contemplates her future with Sam after learning heartbreaking news. Andy meets a teen in need of protection.

Andy and Sam return to work; Andy is attacked at Traci's place and Sex Crimes Unit tries to take over the case

Nick receives new information on his tragic past, and goes off the grid to track someone down; Nick is forced to tell Juliet about his secrets.

Andy and Sam are shocked to learn that Oliver is the prime suspect in IA’s corruption investigation into 15 Division. What’s worse, they only have until end of day today to find Chris Klem – the missing explosives-dealer – and clear Oliver’s name before he takes the fall.

Dov and Andy cover a music festival where a girl ends up dead due to drugs. Gail goes to court and is unsure whether lying for her brother is the right thing to do. Nick gives Juliet another chance.

Andy McNally’s first shift on the job turns into mayhem when shots are fired in a downtown rooming house. In the midst of the chaos, Andy triumphantly makes her first big arrest – a suspected drug dealer – who turns out to be Sam Swarek, an undercover officer from her own division. She makes up for her grave mistake by going face to face with a dangerous gunman who already has one man’s blood on his hands.

A community-outreach baseball game is interrupted by a drive-by shooting. Sam plans a getaway with Andy.

With Fite Nite looming, Inspector Jarvis sends the officers of 15 Division to seize all "proceeds of crime" – anything purchased with money earned illegally. But when Andy and Nick's seizure at an illegal gambling house leads to a suspicious confession, Andy recruits Sam to help figure out who's lying, why, and where the money is, before anyone gets hurt.

A routine drug bust turns into Traci's first murder case; Swarek, Oliver, Chris and Dov spend a weekend at Oliver's cabin; Andy and Sam both have confessions to make.

Andy answers a domestic disturbance call to find the social worker on the scene is her estranged mother; Sam, Nick, Chris and Gail search for a mother and her two children; a stash of guns recovered by Detective Barber turns up on the streets.

When 15 Division goes undercover at a club-land bar that's a possible hub for illegal handguns, Chris's erratic behaviour and concern for a specific drug dealer make Dov suspicious. Meanwhile – after learning Duncan has made serious professional allegations against her – Andy decides to help Sam with a missing person's case that takes a dark turn.

As the other rookies hunt down a dangerous escaped convict, Swarek drags Andy through his undercover haunts on a mission he won’t explain. At first, Andy assumes Swarek is a rogue cop trying to settle scores from his undercover days. Then she realizes two things: he’s actually trying to track down a missing informant whose life is in danger now that his cover has been blown; and, that there is an undeniable attraction between them.

As the officers of 15 Division try to hunt down the killer of Brian Gowdy, Andy and Sam go on the road to interview a list of inmates at Millburn Penitentiary. All are known associates of the prime suspect; one person on that list happens to be none other than Jay Swarek, Sam's elusive father.

Dov suspects Chris isn't ready to get back on the right track; Steve tells Traci he's about to raid a gambling den frequented by her husband.

A home invasion at an upscale address leads to a massive first response call that brings out the training officers in full force. After the scene is cleared, Andy and Traci remain behind with the terrified homeowner. When Traci is called away to deal with an emergency with her son, Andy is left alone to face the armed thief who is still prowling around the house.

Andy’s undercover skills are tested – and found to be lacking – during a citywide campaign to clean up the streets, when she’s tapped to pose as a prostitute in order to arrest unsuspecting johns. But the real test comes when Andy and Dov inadvertently put a vulnerable street informant’s life in danger, and it’s up to the two rookies to infiltrate a dangerous gun deal in order to save the trapped woman from a group of ruthless criminals.

Andy and Sam are shocked to learn that Oliver is the prime suspect in IA’s corruption investigation into 15 Division. What’s worse, they only have until end of day today to find Chris Klem – the missing explosives-dealer – and clear Oliver’s name before he takes the fall.

Andy’s romance with Det. Luke Callaghan gets complicated when he chooses her for a special assignment - serving a search warrant for a bullet lodged in the head of a witness to murder. When the witness escapes, Andy risks her life to apprehend him, but later finds herself at odds with Luke over the next steps in the case. Meanwhile, the other rookies discover the shocking truth behind evidence from a fatal traffic accident.

After losing a key witness in an upcoming trial, officers from 15 Division must turn to a man who claims to be psychic.