Casey faces pressure to cover for a cop's son, who was responsible for a drunken-driving accident that left a teenager paralyzed. Meanwhile, Severide ignores his doctor's warnings that his neck injury may never heal if he doesn't seek treatment; and Mills must choose between working at the fire department full-time or helping his mom with her restaurant.

At the site of a train accident, Peter Mills becomes deeply upset when he observes the dead body of a young victim. Unable to shake his emotional distress about the event, he questions his future as a firefighter. Dawson and Shay save a 6-year-old girl whose mother is abusing her – but their confrontation leads the woman to resort to dire actions. Meanwhile, Severide aggravates his injury while rescuing a heart attack victim and Shay sends Clarice, her married, pregnant ex-girlfriend, back home to her husband.

After he's injured in a terrible fire at an auto machine shop, Jose Vargas is forced to go on disability and leave his life as a firefighter behind - a task he finds incredibly difficult. Chief Boden tries to help a suspected teenage firebug. Also, Severide receives an enticing invitation from Renee, a woman who he saved from a car crash incident involving live electrical wires. Meanwhile, Cruz tries to save his younger brother Leon from the gang he is involved with.