Following an injury in the aftermath of an industrial fire, Severide and Seager work together to investigate an anonymous tip. Kidd searches for the right person to fill the open spot on Truck 81.
Severide and Kidd investigate an explosion at a jewelry store. Cruz and Chloe take steps to make Javi a permanent part of their family. Gallo, Ritter, and Mouch try to bond with Carver.
Violet clashes with her new partner; Severide discovers a hidden stash of money on a call and squares off against the cops; Mouch gets a parking ticket.
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 in a call, he turns to Severide to protect him. Hermann searches for the perfect scent to spice things up with Cindy.
State Police impede Severide's investigation of a suspicious fire at a storage facility that uncovered ghost guns, Carver is back on thin ice with Kidd and Mouch has a winged nemesis at the station.
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 mishap on the aerial ladder in the midst of a fire leaves Mouch shaken and questioning his abilities. Kidd looks for support from Severide while Casey and Brett discuss their future.
Severide and Kidd work with CPD regarding a suspicious car wreck. Hawkins and Violet's relationship is in jeopardy. Chloe and Cruz adjust to a new family dynamic.
Truck and Squad clash after a tense call rescuing a doomsday prepper. Herman struggles with Cindy's diagnosis. Violet gives Brett and Gallo dating advice.
Boden, Ritter, Herrmann and Kidd work together to take down a local politician responsible for a chemical fire. After his aunt's accident, Gallo worries about their future. Brett steps in to perform Dylan's magic show when he's out of town
Carver deals with the fallout of his arrest. Brett searches for closure with the baby she rescued. Capp weasels his way into the Firehouse 51 group chat.
After their defibrillator malfunctions on a call, Brett and Violet search for answers; Herrmann tries to find the perfect home for his new recliner; a secret from Gibson's past comes to light.
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; Carver's allegiances are torn.
A series of false alarms at a private school hinders the firehouse's ability to respond to legitimate emergency calls. Kidd asks for ideas to surprise Severide on his birthday. Cruz and Brett rent out their extra room, but the new tenant is more than they bargained for.
While completing a task assigned by headquarters, Boden makes an unforeseen connection. Gallo's forced to make a surprise rescue to one of their own when the firehouse is called to the site of a construction explosion. Mouch reignites an old feud.
Gallo makes a split-second decision during a dangerous fire rescue leaving Casey steaming that his direct orders were not obeyed. Kidd feels a strain in her relationship with Severide. Brett and Mackey find themselves searching for answers following a series of suspicious calls.
