Daniel Kyri

Severide must make a tough decision about the future of his career at Firehouse 51; Herrmann deals with the consequences of his temper; Cruz is excited to demonstrate the Slamigan at the Firefighting Expo; Commissioner Grissom returns.

Severide starts off on the wrong foot at his Office of Fire Investigation assignment when, despite orders, he reopens an old case; Herrmann is on a mission to discover what caused an apartment fire; Kidd finds herself burning the candle at both ends.

Casey further investigates a motorcycle accident at the request of the victim's son; Kidd, Foster and Brett bond while helping Kidd fix a mistake; Mouch and Otis have a falling out after Otis' teasing hits a sore spot.

Severide and Boden search to uncover whether arson was the cause of a fire at a hair salon; Mouch, Herrmann, Otis and Kidd make a startling discovery while tracking down the missing piercing nozzle from Engine 27.

The surprising arrival of a new fire truck brings both joy and chaos to members of Firehouse 51; Boden and Severide are asked to make peace with an old foe for the greater good; Brett receives family news while Foster plans a party with friends.

Cruz and Severide suspect foul play when a fire started by an elderly woman turns deadly. Kidd, Foster and Brett create a women's-only lounge. Firehouse 51 celebrates some good news.