Nazdarovya!

Pilot. Firehouse 51 works to regroup after a tragedy strikes in the Series Premiere.

Mon Amour. Firehouse 51 works to regroup after a tragedy strikes in the Series Premiere.

Professional Courtesy. Casey is pressured to cover up for a drunk driver.

Professional Courtesy. Casey is pressured to cover up for a drunk driver.

Hanging On. Voight's harassment towards Lieutenant Casey escalates.

Rear View Mirror. An out of control apartment building fire finds Casey laying it all on the line.

Two Families. Thanksgiving proves to be a busy holiday for the firehouse.

Leaving the Station. A train accident leaves Mills doubtful about his future as a firefighter.

It Ain't Easy. An injured firefighter faces life after the job.

Merry Christmas, Etc. Firefighters face theft accusations and an investigation.

God Has Spoken. Cruz struggles with guilt over Flaco's death.

Under the Knife. Severide (Taylor Kinney) faces the consequences of his injury -- and an uncertain future.

Warm and Dead. Chief Boden tries to remedy a situation involving a suspected teenager.

A Little Taste. Tensions rise when Severide (Taylor Kinney) crosses paths with someone from his past.

Nazdarovya!. Dawson puts herself in danger to help her brother.

Viral. Cruz's torment jeopardizes his fellow firefighters.

Better To Lie. Past tensions resurface between Chief Boden and Bennie Severide.

Fireworks. Mills pushes to learn the real story of his father's death -- Treat Williams guest stars.

A Coffin That Small. A firehouse rescue call leaves a lasting impression.

Ambition. Mill's drive to join Squad creates friction within the Firehouse.

Retaliation Hit. Serveride is met with unexpected news, as Voight returns.

Leaders Lead. Severide pulls out all of the stops in hopes of resolving his problems.

Let Her Go. Casey learns that old habits die hard when he is left to deal with Voight.

A Hell Of A Ride. In the Season Finale, a call to the local penitentiary places the squad at risk.