DuShon Monique Brown

Firehouse 51 responds to a dangerous structure fire that leaves one of their own in jeopardy. Borelli confronts Boden about his brother's death.

Kelly is a law unto himself in his pursuit of Katie's kidnapper, while Dawson's grudge against Rebecca grows when she joins Firehouse 51.

Severide and Stella keep an eye out for Grant; Louie has Dawson questioning her dangerous career path; Casey's relationship with Susan Weller cools down; tensions between Borrelli and Boden reach a boiling point.

Dawson is rattled by a suicide note she receives in the mail. Is it too late to intervene? Meanwhile, Casey contemplates a life-changing purchase.

Severide sticks his neck out to help a drug addict and Jones questions her career choice as her dad's meddling takes its toll.

The crew grow anxious following Brett and Mill's disappearance. Casey and Dawson reach a decision about the future of their relationship.