The officers are trying to move on with their lives in the face of a tragedy when they discover a police laptop has been stolen, containing sensitive information. They set off on a hunt to recover the computer and prevent any dangerous fallout. When Andy, Nick and Swarek uncover a drug informant who may have been compromised by the leak -- and when Sam suspects the informant's motives -- it drives a wedge between Andy and Sam, unleashing pent up emotions.

Weeks of trials and tribulations come to a head when the rookies of 15 Division are left on their own and a frenzied night in the station culminates in a prisoner pulling a gun on Chris in cells. The ensuing inquiry has Internal Affairs looking for someone to blame. With careers on the line, the rookies reflect on the personal and professional choices that have led each of them to that night's events, walking a fine line between telling the truth and having each other's backs. Meanwhile, Gail is still trying to recover from her harrowing abduction, Chris is blindsided by a personal revelation, and Andy learns a secret about Nick's past.