A familiar face returns to Firehouse 51 to serve with Kidd on a special task force. Mouch and Capp work to keep Tony safe, as he’s days away from breaking…

Boden, Ritter, Herrmann and Kidd work together to take down a local politician responsible for a chemical fire. After his aunt’s accident, Gallo worries about their future.

Facing suspension, Dawson gets a hand from the same girl she saved through the procedures that landed her in front of the disciplinary board. Lieutenant Casey finds his fuse shortening…