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.
Herrmann investigates the rise in missing fire hydrants and teams up with Kylie to track them down. Kidd's cousin comes to town, revealing surprising family history. Violet and Novak treat the victim of a birthday cake smash gone awry.
After a daring rescue at an adventure park, Kidd asks Severide to create a ropes course for Girls on Fire; Violet's former nemesis returns, pleading for her help; Herrmann creates a signature cocktail for Molly's.
A surprise visitor from Novak's past joins Ambo for a late-night ride-along; Herrmann faces a mountain of Chief-level training records and incident reports; Violet catches Carver in a lie.
In the face of adversity, Pascal searches for justice. Violet struggles to write a letter to Carver. Damon returns to the floater pool hoping to secure a permanent spot at 51.
Kidd helps a teen drawn to Girls on Fire, while Cruz, Capp and Tony anticipate testing Squad's new saw. Violet and Novak puzzle over a collapsed bodybuilder at the gym.
Deputy Commissioner Boden returns to Firehouse 51 to investigate a disastrous firefight and the surrounding mystery that left one of their own in peril.
Severide investigates an old house fire from 10 years back in which Kidd had responded; Carver and Violet search for a mystery medic who abandoned a victim; Novak looks for a roommate.
With the crew stretched thin, a performance efficiency expert evaluates Firehouse 51. Severide and Kidd attend the birth of the baby they hope to adopt.
Kidd strengthens her bond with Natalie during a road trip. Severide investigates a car fire and uncovers surprising evidence. Violet receives a career opportunity after being featured in a local newspaper.
Severide puts his job on the line to help out one of their own. Kidd navigates Natalie's complicated relationship with her sister. Herrmann prepares to take the Chief test.
