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.

When Traci and Andy are sent out on an undercover training exercise, they stumble upon a young woman who is about to die of an overdose. Meanwhile, Dov finds himself on a “ride-along” with a drug dealer and old friend of his deceased brother. Back at the station, Chris and Gail deal with a teenage boy they found tied up at a graveyard; sifting through the wreckage of their relationship, to try to get to the bottom of a bullying situation.

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.

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

Andy and Officer Cruz butt heads when a disturbed woman forces them to make a crucial decision; an armed burglar is sought after a string of ATM robberies; Dov and Chloe have to work together.

When a missing persons case is reopened, Swarek teams with his training officer to solve it; Chloe and Dov deal with a witch and her client.

It's a day of firsts as Oliver gets promoted to Acting Staff Sergeant and Andy is tasked with training 15 Division's newest rookie, Duncan Moore. But when Andy and Duncan respond to a messy homicide at a pawnshop, it's clear this rookie is going to give Andy the challenge of a lifetime.

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…

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.