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.
In the wake of a targeted attack on the officers of 15 Division, Andy, Swarek, and their fellow officers have to piece together the truth about a past crime in order to find Oliver Shaw - in time to save his life.
Oliver Shaw is taken hostage and used as a decoy for Kevin Ford's ultimate plan to seek revenge on the officers at 15 Division - specifically those who were involved in questioning his involvement with the abduction of Chris Diaz's son. Many of 15's officers are sequestered to the station to be kept safe from Ford's attacks.
When Andy and Chloe respond to a routine 911 call, they are blindsided by an unseen shooter out for revenge.
After Andy and Chloe take fire from an unseen shooter, the officers realize they are the targets of someone with a grudge against 15 Division. They must continue to serve and protect while in the line of fire.
Andy and Chloe are blindsided when they respond to a routine 911 call and an unseen shooter gravely wounds Chloe. After shots are fired at a subsequent emergency call, the officers realize they are the targets of someone with a grudge against 15 Division. Now they must continue to serve and protect the community while in the line of fire - and hopefully figure out who is hunting them before anyone else gets hurt.
Andy finds out Marlo has been carrying out an unauthorized investigation.
When a suspected pedophile is found beaten within an inch of his life, Andy discovers Marlo has been conducting a mania-fueled, off-hours "investigation" into the man for days. Andy and Swarek must scramble to cover for Marlo's unprofessional conduct and find the real assailant, before Marlo is exposed.
Marlo reveals to Andy that she's been watching suspected pedophile Kevin Ford for days. When Andy answers a home invasion call and finds Ford badly beaten, she fears the investigation will point back to Marlo. Meanwhile, Traci oversees a major drug sweep, with Chloe, Nick, Dov and Gail assisting. 15 Division is poised to break the single week record for drug collars, but when Sam leaves his post with Traci to help Marlo, the operation takes an unexpected turn.
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.
Near the end of shift, 15 Division busts a marijuana grow-op - a case that becomes Traci's first homicide and forces Andy, Nick and Gail to work overtime. Meanwhile, Swarek, Oliver, Chris and Dov head off to Oliver's new cabin for a confessional day of generator repair and male bonding.