After Ali hits a young boy with her car after having a fight with Simon, she soon finds herself not only fighting to prove her innocence, but also fighting to get her job back, which she was stripped of without her knowledge while on vacation. Cold Squad has been turned into a provincial task force, and the only member of the old guard left is Logozzo, so Ali has to prove herself to Coscarella, the new sergeant in charge.

With her life in shambles and Det. Logozzo in the hospital after the warehouse shooting, Ali spends most of her time with her partner. Simon is somewhat involved in the investigation, but most of this episode is used to introduce the new characters in the series as they try to solve an old murder that has connections to the boy Ali hit. It turns out the youngster had a weapon and it is tied to the murder. Meanwhile, Simon tries to patch up things between him and Ali and learns where Ali was when she was supposedly on vacation ... she had an abortion.

Ali and Frank are assigned to find out who murdered plastic surgeon Marvin Michaelsen after a drug dealer identifies him as the man who removed his fingerprints, but the tension between the two soon ends up taking a higher priority than the investigation. Nicco and Mickey work together on the case of Dermot Wells, a garbage collector that is believed to have murdered his former co-worker, and make a bet on how soon they'll get a confession.

Ali and Frank investigate a rock star accused of murdering a woman who fathered his child -- a woman he swears he never even met. While trying to figure out what Nicco does with his time, Mickey investigates the case of a woman who comes in and tells them her husband killed a baby.

An 18-year-old girl agrees to allow the man who raped her,Lance Rivet, to go free after the mother of a rape victim convinces her that he has information that could nail her daughter's rapist and murderer, Rivet tells them that T.J. Larper killed her and another girl but evidence reveals that Lance committed one of the murders himself. Unfortunately, they can't touch him.

Ali and Bill investigate the death of Sarah Mills, who was found in a warehouse 3 years ago. Nicco and Mickey join forces with Frank to investigate the death of Liam Skyler, the main suspect being the former roommate, Tessa Yale. When problems with his son come to a head, Frank takes a leave of absence from the squad.

While I.A. investigates Ali for shooting at a man she thought was holding a gun (it was a remote control), Mickey and Nicco do stakeout duty together looking for Kirk Lennox and get on each other's nerves. Ali pairs up with Bill while reinvestigating the murder of Clara Pritchard, while Mickey comes under fire from Nicco, who wants her to lie and support Ali's original belief that the man was holding a gun. When Nicco learns that Mickey is sleeping with Bailey Gallanson, he berates her for refusing to lie for Ali yet being willing to sleep with Gallanson, who is not only married but has young children.

Nicco and Ali investigate the unsolved murder of Jeff Steeves, AKA. Vulse G, after a car is found underwater. The car leads them to an elderly woman named Clarice Fry, which eventually leads them back to her grandson Timo, who has a connection to Jeff's former manager, Desecrate. Mickey is assigned to work the case of Lester Graham, a gambler who owed $20,000 to an on-line gambling company who is rumored to be very violent in their collection methods. Mickey is upset when Bailey asks her to San Francisco then takes his wife instead, but shrugs it off to Nicco.

Nicco has a lot of trouble dealing with the case of a teenage girl who was murdered, remembering a girl in his past that went missing. When queried by Sam, he admits that this is his first kid case. Mickey and Ali investigate an American serial killer who claims to have murdered two girls in British Columbia, believing the man is just trying to escape the death penalty. Kyle Bradley identifies one girl as his sister after shown the teddy bear pendant found by her body.

Ali investigates an old film that was discovered in the apartment above Bernice's and looks to be a sado-masochistic snuff film, but her focus is soon on her friend Bill, who finally wants to talk to her about what was going on with him back when a plastic surgeon was murdered (First Deadly Sin) -- he wants to become a woman. Bailey is representing a young woman named Anita Dunn, who is terrified that the man who raped her is back in her life (Deadbeat Walking). Nicco agrees to take on the case, but she gets more attached to him than she should. Mickey isn't sure where she stands with Bailey, and things get hot when Pawlachuk catches them in a clinch.

The squad interrogates four suspects in a 20-year-old murder.

A public outcry follows the brutal murder of a prostitute, which resembles several unsolved killings.

When a woman is murdered by a stalker, new clues emerge in the case of the prostitute killings.