Casey's pancake breakfast gets upstaged by the Alderman's arrival. The guys are debating what to do for Mouch's bachelor party when he breaks the news that Trudy's brother is going to be the best man. They get called to a car accident where a manhole cover blew up and went through a windshield. They get a kid out of the back seat but the father is strapped. More manhole covers start exploding.After getting the dad out of the car, 51 grabs extinguishers and simultaneously fires them into the sewers. Brett and Jimmy take the family to the hospital and Brett's alarms go off when the dad says that the mom is dead after the boy said he wanted to go to his mom's house. Gabby teases Stella about having a crush on Severide who shows up to apologize to her about hitting on her and showing up at her place when she was married. The community organizer, Danny, stops by the firehouse to ask him to reconsider accepting the gang member's support. Hermann complains to the Chief about Mouch's decision., but the Chief sides with Mouch. Trudy drops her brother off at the firehouse -- he's super obnoxious and oblivious. The firehouse finds an anti-Casey billboard outside the house that blasts Casey's mother as an ex-con. Casey goes to Becks' office and demands the billboard be taken down. Brett checks with Maggie about the family from the car wreck, and is only more suspicious when records show that he refused to supply an emergency contact. Logan starts to win Otis over, but the rest of the team is horrified at his bachelor party suggestions. Boden calls Casey in to tell him that the friends of the firemen benefit has been moved because of complaints related to the billboards. The talk is interrupted by a paramedic call -- but the address is just outside the house. A person was dumped out a moving car, beaten, with chains wrapped around them. As the ambulance pulls off, the house finds fliers on all the cars nearby with a picture of Casey and questions about his time working at the strip club. Gabby argues with him when he wants to give up the case. At Med, Roman talks Brett; the man from the car accident has an warrant out for kidnapping his son. Roman and the paramedics catch up to him just as he's about to flee in a cab. He claims his wife is a junkie. Stella's ex shows up at the house, all mopey and needy and looking for some tail. Jimmy and Brett talk about if the dad was telling the truth. Gabby catches Stella and her ex coming out of the ready room, and warns her friend not to get busy at the house. Stella reveals that she was giving him a B12 shot. Logan hands out bachelor party itineraries, and just as Mouch is about to complain to him, they get called out to a fire. There is a car on fire with a man inside; Severide gets him out. Once they extinguish the flames on the man, they notice that he's been tied up and stabbed. Casey notices some gangsters standing behind him as the school across the street lets out. Teddy's mom shows up at the hospital and thanks Brett and Jimmy. Brett confronts her about drug use. Jimmy tries to diffuse the situation, but the woman threatens to have Brett fired. Jimmy tries to talk to her about maintaining distance, and she explains that she can't compartmentalize like that. Casey meets with the gang leaders to broker a deal to keep drugs away from the high school. The ladies all catch up at Molly's and pity the guys, who have shown up at a fancy hotel to find that Logan reserved a suite. When they get to they find that the room is full of strippers, booze, and dance music. Hermann reveals that he knew the whole time, and that Trudy was in on the planning. Gabby and Matt mingle at the candidate forum. The guys stumble out of the hotel.