Voight and Ruzek lock horns over how to handle the aftermath of the Antonio situation. Meanwhile, a series of violent carjackings turns deadly, and Ruzek must rely on a C.I. he grew up with to help solve the case.
An investigation into the death of a well known district attorney puts the Intelligence Division at odds with a mayoral candidate. Antonio returns to work but doesn't trust his own judgment when an operation goes sideways.
While chasing a heroin supplier, CPD crosses paths with a convicted criminal recently released on a technicality. Halstead's history with the man threatens the team's ability to put him back in prison.
Using information from Cruz, Intelligence chases down the robbery crew that's been using the lockbox key. Voight is under pressure to bring the crew to justice without tarnishing the reputation of a murdered firefighter.