Danny and Baez investigate the murder of a single mother whose ex-husband has a history of violence. Also, Frank deals with the fallout when Mayor Dutton eliminates solitary confinement in prisons, and Jamie’s efforts to save a young woman who overdosed on drugs has unexpected consequences.

A case turns personal for Danny when he works to protect a nurse, Faith Madson, from her violent ex-boyfriend. Also, Shelly Wayne, an acquaintance of Frank's, comes to him with a theory regarding the death of an inmate, and Jamie and Eddie help deliver a baby.

After Danny’s brother-in-law, Jimmy, gets caught up with the mob and steals Danny’s credit card, Danny forces Jimmy to take down the mobsters with Baez’s help. Also, Frank has Erin and Anthony investigate if his old partner, Lenny, is truly guilty of a crime and Jamie is approached by Tariq, an officer who wants his help getting reassigned from his undercover assignment at a mosque.