Gabby continues to obsess over Bria, and to not communicate with Matt. She asks for the day off, but doesn't tell him that she's driving out to Joliet, instead relaying that information to Kelly, who is her partner in crime in this endeavour. Kelly feels like he's put in the middle, but explains to Matt that Gabby probably doesn't want to bother him because she knows how he feels about getting too close to victims. Matt is frustrated both by the distance from his wife and the antics of his team, and considers taking a larger, private office outside of the bunk room when Boden offers it up. But when he goes through Gabby's belongings from the bunk room and finds a picture of them with Louis, he realizes that keeping himself apart causes more problems than it solves. Both Gabby and Kelly are unsuccessful in finding Bria, although Kelly tracks her to a visit at her father's rehab facility and Gabby finds out that her mother shot herself when Bria was a 6. When Gabby gets a call from the coroner about a Jane Doe teen with her card, Matt accompanies her to find out if it's Bria.
There's something rotten in Firehouse 51. Mouch and Herrmann are egged on by Otis to discover the source of the odor. After tearing up the bunk room (and attempting some DIY plumbing), Sylvie and Stella call in their new (hot) friend from HazMat, and he quickly discovers the problem. Mr Sprinkles is found decaying in one of the dividing walls. Herrmann is pissed that the animal escaped and died and makes Otis and Cruz pony up $200 donations to the Chicago Humane Society.
Stella fills in for Gabby on the ambo, and she and Sylvie really hit it off. But when they meet a new lieutenant from the HazMat team, the two lonely ladies get a little competitive. In the end, Sylvie talks Stella up to HazMat Zach and gives him her number.