S4, E14: Lt. Severide (Taylor Kinney) confronts Chili (Dora Madison) about his suspicions regarding her erratic behavior, but she does not take too kindly to his intentions. Meanwhile, members of the firehouse rally around Lt. Casey (Jesse Spencer), who they believe is a perfect candidate to run for the position as Alderman, and Jimmy (Steven R. McQueen) faces off against Antonio (Jon Seda) in the first annual "Battle of the Badges" boxing match.