Alex Weisman

Burgess and Atwater come across a gunshot victim and the only witness is Olinsky's daughter, and Ruzek goes to Burgess for help with an undercover mission.

The shooting of a child in their neighbourhood forces Cruz and his brother to think about the gang, Isabella gets Mills to dress up for a gala, Casey feels sad he will be seeing Dawson less, and Shay gets in deeper with Devon.

Casey makes a choice he later regrets at the scene of a car crash. Severide opens up old wounds as he investigates his findings in the lock-up.

The firehouse crew goes to the scene of a railroad accident; Boden must make a big decision about his future; Severide learns more about the woman he saw with his father; Shay and Dawson continue to butt heads.

New-to-the-crew Sylvie shines as the crew answer three dramatic call-outs. Casey asks Newhouse to help dig up dirt on his sister's husband.

A member of Firehouse 51 becomes the victim of a vicious attack, and Brett and Jimmy worry about Chilli's behaviour.