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.

Events force Lieutenant Casey to team up with the Intelligence Unit, now run by Voight, who doesn’t appear to have changed his crooked ways after his stint in prison. Shay's excitement at the prospect of becoming a parent grows, while Mills and Dawson face some personal challenges. Meanwhile, the house comes together to support the opening of Molly's.