Daniel Kyri

Casey and Severide disagree on a call, while Boden starts a diet and Brett's birth mother shares life-altering news. A familiar face has a proposition for Herrmann.

A suburban house fire involving a mother and son hits home for Casey and Gallo. Meanwhile, Kidd has a charitable idea to help give back to her community.

An unexpected visit throws Casey for a loop and Severide sets out to exonerate a wrongly convicted arsonist. Kidd pays the price for burning the candle at both ends, while Cruz goes on a mission to fix one of Otis's old toys.

Members of Firehouse 51 are dismayed to learn their boundaries have been redrawn to overlap with an adjacent station, and problems quickly arise. Casey and Gallo hunt a missing piece of equipment. Brett and Foster find themselves at odds.

Some members of Firehouse 51 get sleuthing after catching wind of a Reddit post involving one of their own. Brett continues to get invested in her birth mother, Julie.

A rare but deadly bacteria takes its toll on numerous victims around the city, leaving Chicago's finest first responders to work together alongside the CDC to resolve the dangerous situation. Severide suspects something bigger is happening.