Chief Boden makes a risky last minute decision to save his men; Dawson continues to deal with her father; Brett's childhood friend visits and strikes the attention of someone within the firehouse; a fire at a high school hits close to home for Boden.
Chief Boden turns up the pressure on Severide and Casey to investigate the cause of the fire that trapped his wife; Mouch is over-competitive in the firefighter muster challenge.
Casey gets off on the wrong foot with a new chief; Casey makes a risky move to save a man threatening to jumping off a building; Mouch flies in Cruz's brother Leon as a birthday surprise; Brett learns new information about her friend Hope.
While running a secret errand, Dawson finds herself trapped in a collapsed parking structure; pressure mounts on Casey as he begins taking on additional duties; Kidd grows increasingly skeptical of Hope.
Casey and Severide find themselves at odds after Casey argues about how to save a teenager entangled in barbed wire; Otis tries to convince Casey to participate in the beta test for an expensive piece of new firefighting equipment.
Kidd is surprised to discover she is being transferred out of the firehouse; Severide and Casey are suspicious and investigate; Otis and Herrmann discuss taking over a rundown bar; Dawson's frustration with her father reaches a boiling point.
Brett attempts to make a lifesaving decision; Otis prepares for the grand opening of Molly's North; Boden becomes emotional following the rescue of a famous blues player; Dawson tries to come to terms with how she has been dealing with her father.
Dawson must make a tough decision about a father who is addicted to painkillers; Herrmann gets into an altercation with a police officer; Otis and Cruz go on a mission to find out who Brett is dating; Donna's brother unexpectedly comes to town.
Dawson asks Severide for help; Brett and Kidd compete for Zach's heart; Otis, Herrmann and Mouch try to figure out the source of a terrible stench wafting throughout the firehouse.
Dawson and Casey try to find Bria's whereabouts; Lt. Severide reunites with Chief Grissom; Cruz enlists the help of Brett and Mouch to create a new tool; Kidd and Zach go on a date.
After responding to a time-sensitive rescue, Casey and Severide don't see eye to eye on the best course of action; Herrmann struggles to entertain his daughter while at work; Brett is joined by a surprise guest during a spa getaway.
After photos of Casey and Severide jumping off the roof during a heroic rescue make the front page of the newspaper, Boden unwillingly agrees to have the photographer chronicle a day at the firehouse.
Chief Boden unwillingly agrees to let Dawson and Brett go under cover; Kidd and Zach's relationship hits a bump; Cruz has a hard time expressing his true feelings for Brett.
After responding to a car accident, Casey and Dawson become skeptical when a domineering husband continues to answer for his injured wife; Cruz is frustrated with Herrmann and Mouch; Kidd uncovers something meaningful to Severide.
Otis and Kidd's lives are put in jeopardy when there's gunfire inside a house; Dawson comforts Brett during an especially trying time; Casey begins to notice that romance might be going on within the firehouse.
The crew struggles to come to terms with an injury to one of their own; a temporary replacement must be dealt with; Boden ponders some interesting news; Kidd has a hard time keeping a secret.
Boden has a lapse in judgment in the aftermath of rescuing a young boy; Kidd struggles to win the approval of Severide's mom after a surprise visit; Otis takes on new responsibilities at the firehouse.
When the FBI takes over the firehouse for an undercover mission, Casey and Severide volunteer to assist with the investigation; Kidd attempts to help Severide come to terms with recent developments he's been managing.
The team responds to a residential fire at a property belonging to a drug cartel; a hefty amount of money is missing from the crime scene; Kidd makes a big decision.
After saving a girl from a car accident, Boden and Severide receive a surprise package; Brett struggles to keep quiet about Cruz reacquainting with his now-married high school sweetheart; a crisis brings Bria back into Dawson's life.
Lt. Severide is shocked when Rene Royce resurfaces; Casey comes up with a plan to help Chief Boden in his latest pursuit; Kidd regrets a decision she made regarding Severide; Herrmann clashes with Lt. Colannino over their son's basketball team.
Boden takes a big step in the pursuit of a major career decision; Kidd becomes increasingly distrustful of Renee's motives with Severide; Herrmann has trouble bouncing back after a tragedy.
Boden's chances for a promotion are met with potential complications; Dawson and Casey don't see eye to eye on an important decision; Kidd finds herself struggling to find time with Severide; Brett and Dawson respond to a tough call.