Boden suspects his neighbor is setting him up; Severide, who's still on probation, receives a surprise visit from his father and also learns something about Patterson that could be a game changer. Romance blossoms at a fire department gala.

Severide and Cruz find a child's remains inside a chimney while investigating a possible carbon monoxide leak inside a home. In other events, Casey braces for the worst in his run for alderman while Alderman Becks continues to bad mouth him to the press.

It's a family reunion when Dawson and Antonio's mother and father come to Chicago for their big anniversary party, but things quickly turn south. When a deep secret comes to the surface involving his stepson James, Chief Boden decides to take matters into his own hands. Meanwhile, Casey tries to save a young boy during a harrowing call to a warehouse and Otis and Kidd become competitive at the mud-hundred race.

When similar car accidents uncover the fact that someone may be targeting innocent people, a determined Dawson takes matters into her own hands to help push things along. Severide does everything he can to make Anna feel welcome in her new Chicago surroundings. Herrmann, Kidd and Dawson decide to have Molly's included as a stop in this year's pub crawl. Meanwhile, Casey tends to his Alderman's duties when a persistent constituent asks for his help in resolving an issue.