The members of Firehouse 51 struggle to cope when one of their own dies in a fire, while lieutenants Casey and Severide blame each other for the tragedy.
Severide hides his serious shoulder injury as he tries to rescue a construction worker from a collapsed building; two teens become trapped in a vehicle.
Casey must decide whether or not to turn in a dirty cop's son who paralysed a teen in a drunken-driving accident; new girl Nicki pays Severide special attention.
Peter is deeply shaken by the dead body of a young victim; Severide's injury is aggravated.
Severide is made an enticing offer by a woman he saved from a car crash while the crew bid farewell to a colleague after a blaze at a garage.