The second half of a crossover with Chicago Fire , focusing on a hospital bombing investigation.
Antonio’s son is kidnapped by the cartel, forcing the team into a desperate search.
as Officer Adam Ruzek: A rookie recruited straight from the academy by Olinsky.
as Officers Kim Burgess and Kevin Atwater: Patrol officers working to prove themselves and move up to Intelligence.
as Trudy Platt: The sarcastic, no-nonsense desk sergeant (recurring in Season 1, later a main cast member). Episode Guide Summary
as Detective Jay Halstead: An ex-Army Ranger and Lindsay's partner.
as Detective Antonio Dawson: A dedicated family man who often serves as the moral foil to Voight.
The season finale involves a massive manhunt for the escaped cartel leader Pulpo and a shocking betrayal within the unit.