Boden, Kidd and Severide work together to protect one of their own; at the Fire Academy, Herrmann meets an inspiring young man; talk of the annual CFD Gala dominates the firehouse.
The big wedding day arrives and Firehouse 51 welcomes Casey back to celebrate the joyous occasion; Emma's plans to replace Violet come to a shocking end.
Firehouse 51 prepares for their semi-annual firehouse inspection; Brett fights to save her paramedicine programme; Commander Martin Pearce asks Severide for a favour.
Truck and squad clash after a tense call rescuing a doomsday prepper; Herrmann struggles with Cindy's diagnosis; Violet gives Brett and Gallo dating advice.
Firehouse 51 helps Herrmann put on a school fundraiser; Carver's troubled brother comes to town; a grateful citizen is determined to thank Brett and Severide for saving his life.