Mark Vallarta

When a fire claims one of their own, there’s plenty of guilt and blame to go around. Lt. Matthew Casey (Jesse Spencer), in charge of the Truck, tries to carry on, but clashes with the brash Lt. Kelly Severide (Taylor Kinney) of the Rescue Squad -- and each blames the other for their fallen team member. Adding to the turmoil, Casey, unbeknownst to his colleagues, is in the midst of a separation from Hallie (Teri Reeves, "Three Rivers"). The firehouse also includes: Battalion Chief Wallace Boden (Eamonn Walker), a fireman’s fireman who is confronted by important personal decisions; paramedics Gabriela Dawson (Monica Raymund) and Leslie Shay (Lauren German), who share a close bond and team together to face some of the most harrowing situations imaginable; Peter Mills (Charlie Barnett), an academy graduate who is the latest generation in a family of firefighters; and Christopher Herrmann (David Eigenberg), a seasoned veteran who loses his home to foreclosure and now must uproot his family to move in with his in-laws.

The Fitori murder case is brought to the intelligence unit and Voight's (Jason Beghe) son, Justin (guest star Josh Segarra), may be involved. Gradishar (guest star Robin Weigert) fills Antonio (Jon Seda) in on the arrangement between Internal Affairs and Voight which increases friction between Voight and Antonio. Back at the precinct Ruzek (Patrick Flueger) helps Burgess (Marina Squerciati) get back at desk sergeant Platt (guest star Amy Morton).

In order to get Abruzzi back in command of the prison’s work detail -- and the escape plan back on track -- Michael must give up Fibonnaci’s location to Philly Falzone. Meanwhile, Michael and Dr. Sara grow closer as the escape gang grows by one. Outside the walls, Kellerman and Hale get some unwanted help tracking down LJ, and Veronica and Nick make a breakthrough.

Ruzek reunites with an old colleague to take down a crime ring but when things don't add up, Voight and Burgess do some investigating of their own.

After a teenage boy is brutally murdered while spreading the word of his church in Chinatown, Detectives Wysocki and Evers enlist Superintendent Colvin to gain the cooperation of locals. When the unofficial mayor of Chinatown is uncooperative, Alderman Gibbons is called upon to broker a deal that accelerates the investigation. Meanwhile, Teresa’s brother-in-law (guest star Rockmond Dunbar) rolls the dice with a shady business deal, and Liam goes even deeper undercover.