A new chief shakes things up at Firehouse 51. Violet and Novak work to uncover the truth behind a car crash. Cruz keeps a watchful eye on Severide and Damon’s growing bond.

After Damon disobeys Kidd’s orders on a call, he turns to Severide to protect him. Herrmann searches for the perfect scent to spice things up with Cindy.

Severide and Van Meter investigate a fire at a family-owned restaurant. Pascal questions Kidd’s leadership.

Violet risks her job to deliver a baby on a tragic call. Mouch, Capp and Tony help Cruz track down Javi’s stolen bike.

Kidd and Severide investigate a trucking company responsible for a string of accidents. Herrmann recruits Kylie to help get new radios. Firehouse 51 celebrates Violet’s birthday.

Severide gets wrapped up in an Illinois State Police investigation after discovering illegal guns on a call. A bird harasses Mouch on the apparatus floor.

Pascal and Severide revisit the storage facility fire in hopes of uncovering new evidence. Cruz helps Mouch take his studying to the next level.

Herrmann and Mouch prepare to take their officer exams. Cruz receives a chilling omen. Carver takes care of a dog after its owner is injured on a call.

Cruz’s past comes back to haunt him. Severide prepares to teach an arson class at the academy. Mouch searches for a victim’s next of kin.

The team responds to a crisis at a community center. Severide is forced to investigate one of his own Squad members. Kidd helps a teacher going through a post-incident spin-out.

Chicago's first responders unite in the wake of a catastrophic gas explosion and fire that threaten a city government building. Herrmann reluctantly shadows Pascal while Violet, Novak and Dr. Frost take charge of triage efforts on site.