The episode started with Casey getting out of the girl from the luau's (Beth) bed. They start talking and she tells him that she is about to get a divorce, and her ex is going to be signing the paper tomorrow.
At the firehouse Boden announces that his father passed away and he will be taking some time off from the firehouse. He introduces Bridgen and says that he will be covering for him as chief while he is away. After Boden leaves, Welch shows up with his gear and says that he has been assigned to their firehouse while Newhouse is away. Casey and Dawson go into the Chief's office and tell him that they can't work with him. They tell him about the accident that Welch caused. The chief says that Welch is a good firefighter.
Severide then asks Casey where he has been because he hasn't been home since the luau. Casey tells him that he has been with Beth from the luau.
Brett is surprised when the girl that she saved last week, Celia arrives at the firehouse. She thanks Brett for saving her and then gives her a bracelet that she made for her. Then a call comes in and Brett has to leave, so Celia asks her for her phone number, Brett gives it to her.
The call was from a bowling alley and an employee explains that a man named Jerry was working on maintenance and he got his arm stuck in the pin setter. The only things they can see hanging down is his bloody arm. Cruz and Casey head to the back to start taking apart the machine, Severide lays down under the pin setter to talk to Jerry. Mills tells them to hurry because Jerry is going in to shock and he doesn't have a pulse in his arm. Severide uses a saw to cut Jerry free and they pull him out of the pin setter. While they are picking up their stuff, Otis slips on the waxed floor and can't get up, the new fire chief laughs at him and makes fun of him, which doesn't go over well with the other firefighters.
Brett remembers Celia telling her that she lost her guitar while she was high and her mom is really mad at her. So Brett stops at a music store to buy a guitar for her.
Back at the firehouse Bridgen corners Severide and tells him that he did well at the bowling alley. Bridgen cracks more jokes about Otis and announces that his new name is "Gutter Ball."
Casey returns and runs into Beth at the front desk, he's confused how she knew where he worked. Beth says she's not there to see him, that she is there to see her husband about the divorce papers. Casey and Severide are surprised when they realize that her husband is Bridgen. After Beth talks to Bridgen, Casey tells Beth that they can't see each other anymore.
At home Brett rants to Dawson about Celia, she talked to the nurse at the hospital and learned that Celia's mom was more worried about her daughters medical bills than she was whether or not Celia was okay, so Brett bought her a guitar.
Herrmann stops by Boden's house to help him with his screaming baby and confesses that Welch is working at the firehouse. Boden is furious!
Casey heads home and Severide tells him that sleeping with Beth when he was supposed to be dumping her is a bad idea. Casey then gets a phone call from Dawson, the faucet isn't working at her and Brett's house. So Casey heads over to fix it for them. Dawson flirts with him and laughs at him when he gets sprayed with water.
Brett goes to Celia's house to give her the guitar. But Celia's mother Sharon isn't happy that Brett bought it for her. She tells Celia to give it back, that she worked two weeks of overtime to buy Celia her first guitar and she got high and left it on a street corner somewhere, so she doesn't get to have a new one. Sharon then slams the door in Brett's face.
Back at the firehouse Bridgen is making fun of Otis again, he got him a bowling shirt with "Gutter Ball" written on it. Cruz tells him to lay off, then he starts joking that Cruz wears triple XL shirts.
Beth shows up at the firehouse to give Bridgen the divorce papers, she tries to kiss Casey again, he dumps her for real this time. Welch sees it all happening.
Brett is devastated that Celia’s mom slammed the door in her face and wouldn’t let her keep the guitar. Cruz tries to comfort her, and Brett explains that she knows what it is like to be raised without a parent, when her dad was away her mom had a nervous break down and her Aunt stepped in and helped raise her. Cruz encourages her to help Celia, but says she needs to find a way to do it that is not so intrusive and doesn’t hurt her mothers pride.
Bridgen calls Severide in to his office and wants to know what Severide thinks of Casey, Severide says that Casey is one of the greatest firefighters here. Bridgen says that he disagrees, he thinks that Casey is insubordinate and keeps a messy company. Bridgen asks Severide to keep an eye on Casey and tries to bribe him and says it will be worth his while. Severide informs him that “scheming behind closed doors” is not how they conduct business at their firehouse.
A call comes in for a structure fire and they all rush to the house, Severide gets ready to go inside with his team but Bridgen stops him and says that he wants Casey to go inside instead with his squad. Casey is baffled but heads inside with Dawson and Otis. Dawson and Otis begin carrying out survivors and Mills and Brett rush them away on stretchers. Otis heads inside with the hose, and the door shuts behind him in the room where the source of the fire is. The door jams with the hose underneath it and Otis can’t get out, and the water is blocked so he can’t put the fire out. Severide and Welch rush inside when they hear Otis calling for “Mayday” on the radio. They work together to break down the door and drag Otis out of the blaze.
Back at the fire house Casey snaps at Bridgen that they all earned their right to be there and he had to treat them with respect. Bridgen is furious, and orders Severide and Casey in to his office. He sits them down and tells them they have no right to talk to him like that, and he is sick of both of their insubordination, he threatens to write them up and orders them to all go outside and wash the windows of the fire house. Severide argues that it is cold outside, but Bridgen doesn’t want to hear it and dismisses them.
Brett invites Celia to the fire house and tells her that she is going to keep the guitar there and Celia is welcome to come by whenever she wants and play. Celia thanks Brett and tells her how cool she is, and then sits down to play a song.
Outside Severide and Casey wash the windows and laugh at Bridgen, Casey watches through the windows and sees Welch talking to Dawson.
Inside, Welch warns Dawson that Casey was making out with Bridgen’s wife, Beth. Dawson is furious.