Boden makes a decision that impacts the race for Deputy Commissioner. A tense call brings up painful memories for Carver and Damon. Mouch struggles to adjust to the new Truck.
Severide and Violet risk clashing with Paramedic Chief Robinson after Lennox makes a dangerous decision on a call. Capp and Tony attempt to break a world record. Cruz and Chloe's marriage problems come to a head.
Severide goes for an unexpected ride on Truck 81. Ritters' world's collide when his secret cop boyfriend helps 51 track down Severide and the missing rig.
Severide steps in as ranking officer at 51. Kidd fights to save her Girls on Fire program. Cruz's family is threatened when someone from Javi's past resurfaces.
For the firefighters, rescue squad and paramedics of Chicago Firehouse 51, no occupation is more stressful or dangerous, yet so rewarding and exhilarating.