David Von Kampen

After responding to a fire at a property belonging to a drug cartel, Casey suspects Cordova when money is found missing from scene.

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.

Kidd, Seager and Carver investigate a fire at the city stables; Kylie clashes with some of the firefighters over changes due to budget cuts; Herrmann struggles to keep it together as Cindy's condition worsens.

Mouch builds a classic firetruck model for the Deputy District Chief but needs assistance from Gallo and Ritter; Brett and Violet encounter multiple victims with a strange set of symptoms; Cindy's chemotherapy results loom over the Herrmann family.

Cruz leads the charge in getting the firehouse to gear up for the Polar Plunge, and Herrmann has a hard time bouncing back after dealing with a tough call. Plus, Foster's personal relationships begin to interfere with her job.

Severide is shocked when Rene Royce resurfaces at the firehouse and Casey comes up with a plan to help Chief Boden in his latest pursuit.