On the verge of closure, Firehouse 51 bands together in a fight to save the station.
Dawson and Casey's romance escalates while Shay hits rock bottom and goes MIA.
A drive-by shooting forces Cruz to make a big decision while Casey and Dawson struggle to keep their feelings at bay.
Firehouse 51 is thrust into the furnace with a train derailment.
Severide performs the save of his career, while Arthur escalates the stakes at Molly's.
Pressure is on Chief Boden to resign from Firehouse 51, while mobster Arthur squeezes a struggling Molly's for more cash.
The fallout from a deadly routine call causes a rift between Shay and Dawson. Meanwhile, Severide goes stealth in his pursuit of Hadley.
As Molly's bar continues to struggle, Mouch gets a campaign assist, and Severide targets Hadley, while Dawson makes an unexpected move. Guest starring Mena Suvari.
Casey struggles to manage Heather Darden's boys. Meanwhile, Severide goes on the offensive in pursuit of the arsonist.
While Firehouse 51 takes on new blood and new rules to avoid closure, Severide faces a dangerous arsonist.
A compilation of the show's steamiest moments so far.
With tensions still running high between Chief Boden (Eamonn Walker) and Bennie Severide (guest star Treat Williams), things boil over when Mills confronts Bennie about the fire that killed his father. Meanwhile, Severide (Taylor Kinney), Casey (Jesse Spencer) and Bennie uncover the truth behind two mysterious diner fires and Shay (Lauren German) takes a new direction with her plan to have a baby.
Events force Lieutenant Casey (Jesse Spencer) to team up with the Intelligence Unit, now run by Voight (guest star Jason Beghe), who doesn't appear to have changed his crooked ways after his stint in prison. Shay's (Lauren German) excitement at the prospect of becoming a parent grows, while Mills (Charlie Barnett) and Dawson (Monica Raymund) face some personal challenges. Meanwhile, the house comes together to support the opening of Molly's.
A frustrated Severide (Taylor Kinney) turns to an unlikely ally to resolve his current dilemma. Casey (Jesse Spencer) begins to find satisfaction in his personal life, while Mills (Charlie Barnett) and Dawson (Monica Raymund) face personal challenges. Meanwhile, the squad is called to the scene of a harrowing apartment building collapse.
Detective Voight (guest star Jason Beghe) returns, looking to collect on the favor that Dawson (Monica Raymund) owes him for helping her brother, Antonio (guest star Jon Seda). Casey (Jesse Spencer) falls back into old patterns in his personal life, while Dawson, Herrmann (David Eigenberg) and Otis (Yuri Sadarov) become the proud owners of a real neighborhood bar as Molly's prepares for its grand opening. Meanwhile, Severide's (Taylor Kinney) career is threatened.
Mills (Charlie Barnett) finds himself the target of resentment from some colleagues when Severide (Taylor Kinney) supports his desire to join Squad. Tara (guest star Brooke Nevin), a paramedic candidate, joins Dawson (Monica Raymund) and Shay (Lauren German) on the job for a few shifts. Meanwhile, Shay comes to the aid of Cindy Herrmann (guest star Robyn Coffin), who suffers from pregnancy complications while her husband Christopher (David Eigenberg) is out of town. Elsewhere, Dawson and Casey (Jesse Spencer) draw closer as the grand opening of Molly's draws near, and Casey receives a surprise visit.
Learn about the strange phenomenon that hits Chicago every Tuesday night.
David Eigenberg and Eamonn Walker answer fan questions from Twitter.
Watch the show's biggest fire yet come to life behind the scenes.
Casey races against a raging fire to save himself - and a rescued baby - from certain death.
A behind-the-scenes look at the minivan fire Casey and Dawson barely survived. Hosted by Jesse Spencer and Monica Raymund.
Cruz's worst fears come to fruition when a rival gang interrupts Leon's undercover assignment.
An antsy Dawson frets over her next move - until Casey shows up at her doorstep.
Go behind the scenes of Leon's car crash with stuntman Dan Maldonado.
Michael talks about how big the set is.