Erin Breen

While responding to a call, Dawson accidentally hits a pedestrian who steps out in front of the ambulance, and must deal with the repercussions.

Chief Boden unwillingly agrees to let Dawson and Brett go undercover; Kidd and Zach's relationship hits a bump; Cruz has a hard time expressing his true feelings for Brett.

After the squad is unable to save a woman from a burning building, Severide and Casey disagree on a potential arson case.

Chief Boden turns up the pressure on Severide and Casey to investigate the cause of the fire that trapped his wife; Mouch is over-competitive in the firefighter muster challenge.

Severide and Kidd continue to investigate Benny's old arson case, unexpected news leads Brett to ponder a big decision and all hell breaks loose.

Severide finds a connection between a recent salon fire and a case involving a serial arsonist. Plus, Firehouse 51 throws a retirement party.