Daniel Kyri

A rare but deadly bacteria takes its toll on numerous victims around the city, leaving Chicago's finest first responders to work together alongside the CDC to resolve the dangerous situation; Severide suspects something bigger is happening.

The mattress factory fire spirals out of control; truck and squad lay it on the line in hopes of getting the trapped victims out alive.

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.

Cruz leads the charge in getting the firehouse to gear up for the Polar Plunge; Herrmann has a hard time bouncing back after dealing with a tough call; Foster's personal relationships begin to interfere with her job.

When one of 51's own gets injured on a call, Severide becomes obsessed with helping out; Foster contemplates a big decision; Kidd is concerned for one of her high school trainees.

Casey struggles to get Boden to sign off on an energetic new recruit; Foster extends an olive branch to her irritating new medic; Otis inspires Herrmann to seek new partners at Molly's; Brett realizes life in Fowlerton will take some getting used to.