Violet clashes with her new partner. Severide discovers a hidden stash of money on a call and squares off against the cops working the case. Mouch gets a parking ticket.
A hazmat call at a dialysis center leads to a shocking discovery. Boden clashes with Paramedic Chief Robinson. Carver notices a concerning change in Gibson's behavior.
Severide, Kidd and Van Meter investigate a fire at a recording studio. Kylie helps James keep a secret from Boden. Mouch struggles to maintain boundaries with a paramedicine client.
Firehouse 51 welcomes back some familiar faces and says goodbye to Brett. Violet scrambles to decorate Brett's wedding venue. A call at the expo center takes a shocking turn.
After their defibrillator malfunctions on a call, Brett and Violet search for answers. Herrmann tries to find the perfect home for his new recliner. A secret from Gibson's past comes to light.