After saving a young girl, Dawson is forced to make a tough decision when she finds out the girl's father is addicted to painkillers. Herrmann loses his cool and gets into an altercation with a police officer after responding to a call. Otis and Cruz are on a mission to find out who Brett is dating. Meanwhile, Boden is skeptical when Donna's brother Julian unexpectedly comes to town.

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 in tracking down the missing piercing nozzle from Engine 27.

Kidd spreads her wings as a lieutenant. Chief Hawkins rides with Ambulance 61 to learn more about Brett. Casey takes a trip out of town. A Ritter date night turns into an emergency situation.

Severide and Herrmann clash over office space. Boden looks at Pelham’s past as he considers making him permanent. Gallo’s resentment of Pelham comes to a head. Brett and Ritter force Violet to confront her true feelings for Gallo.

Chief Hawkins goes above and beyond to help Brett and Violet with a problem. Kidd pursues an open lieutenant position. A blast from the past asks Mouch and Herrmann for a favor.

Kidd gets a glimpse into Carver's chaotic personal life. Mouch and Herrmann receive an unexpected gift.

Boden, Ritter, Herrmann and Kidd work together to take down a local politician responsible for a chemical fire. After his aunt's accident, Gallo worries about their future.