A gun-smuggling case involves high-caliber rounds; Halstead faces a ghost from his past.
serves as the gritty introduction to the Intelligence Unit of the Chicago Police Department. Premiering on January 8, 2014, the season consists of 15 episodes that establish Sergeant Hank Voight’s morally complex leadership and the team’s "by any means necessary" approach to justice. Core Cast & Characters
The series premiere where the unit hunts a Colombian drug cartel. Adam Ruzek joins the team.
The second half of a crossover with Chicago Fire , focusing on a hospital bombing investigation.