Herrmann and Otis are coaching one of the youth basketball teams and run into trouble with one of the parents, another firefighter, who is too enthusiastic about how the kids play. Herrmann is frustrated with the man until they have a one-on-one discussion and Herrmann realizes that the firefighter is overcompensating for not bonding enough with his older son. They reach an understanding about the team. Soon after, they team up at a fire at a auto body shop and work to locate the mechanic trapped inside. They find the guy, but get separated on the way to the exit. Herrmann gets the victim out, but realizes his friend is still inside. He tries to go after him, but the building blows up. After the flames are out, they find the man, but he's dead. Herrmann feels intense guilt not just because of his personal association with the firefighter and his family, but because the man was found facing the wrong way -- he had turned back looking for Herrmann.
After responding to an accident involving a private ambulance, 51 finds out that the fire commissioner is leaving the position for greener pastures. Casey gets it into his head that Boden should be the next commissioner, and he and Severide campaign on his behalf -- without telling their chief what they're doing. He's upset when he finds out, not liking the perception that he's begging for a job. Casey tries to explain why they think he'd make a great commissioner -- leaving out the part he told Kelly about it being the best thing fo the two of them as well. After losing Herrmann's friend at the auto repair shop fire, Boden agrees to pursue the appointment, but Kelly is surprised to find out that his original mentor, Grizz, is also interested in the job.
Sylvie is outraged that Joe went ahead and slept with his ex, Delia, but even more angry that he lied to her about it. After an initial outburst, she tries to take a nonjudgmental approach with her roommate. But this makes Joe feel even worse than her anger did. Sylvies disappointment prompts him to end things with Delia -- but not before Delia's husband finds them together and gives Cruz a black eye.
Kelly's ex Renee shows up, looking for his help with a case she's representing. Sylvie is insecure about her showing up, especially when she brings her son with her to the fire house. Still, she tells Kelly that Renee doesn't bother her and to do hat he thinks is best in regards to helping her with the case. Sylvie is slightly reassured when she and Kelly attend the memorial for the fallen firefighter as a couple.