Jeff Lima

Severide finally addresses Chief Boden about his injury and makes some important personal decisions about his future. Meanwhile, Casey struggles with family matters and Dawson takes matters into her own hands.

Casey gets off on the wrong foot with Chief Boden's stand in, while Mouch flies in Cruz's brother as a birthday surprise.

Casey's conscience gets put through the wringer when he visits his mother in prison. Cruz shares a secret, and Pete fills in for Shay in the ambulance crew.

A spate of robberies comes to light after a firehouse lockbox key goes missing, and Sgt Hank Voight suspects a firefighter may be involved. With Boden's support, he recruits Cruz to go under cover to help sniff out any suspicious activity.

Tension builds when a group of rabble-rousers attempts to lock down the firehouse. Brett is faced with a monumental decision and Cruz readies himself for a big day. Gallo and Ritter attempt to launch Firehouse 51 into the social media age.

Herrmann and Mouch prepare to take their officer exams. Cruz receives a chilling omen. Carver takes care of a dog after its owner is injured on a call.