Steve Chikerotis

Firehouse 51 must band together when one of its own is taken hostage.

A series of mysterious gas leaks has members of Firehouse 51 puzzled and spread thin; Brett's conflicted when her birth mother gets serious about finding her; Severide misunderstands his role as Cruz's best man; Mouch bites off more than he can chew.

The mattress factory fire spirals out of control; truck and squad lay it on the line in hopes of getting the trapped victims out alive.

Kidd and the team embark on a mission to help Severide as he struggles to process his father Benny's death; Brett suspects a teenage driver in a car accident is hiding something.

Things get personal for Casey and Gallo in the aftermath of a suburban house fire involving a mother and her young son; Herrmann campaigns for more respect; Kidd has an idea for giving back to her community.

Stella Kidd returns to Firehouse 51. The team must work together to put out a potassium fire in a tunnel.