Firehouse 51 responds to a chlorine gas leak at a scrapyard, and an explosion on scene badly injures Capp.
Severide takes up the cause and berates the owner of the scrapyard for dumping hazardous materials.
Severide later goes to talk with an OSHA employee and begs the federal employee to do more than just fine the owner.
When Severide returns to the scrapyard, he finds OSHA has temporarily shut down the place.
Meanwhile, Capp leaves the hospital before being evaluated, and no one knows where he is.
Casey and Severide swing by Capp's place later, and Capp says he's fine.
Capp later has his eyes checked out and tells 51 he'll be back in a few shifts.
Foster reapplies for medical school but is afraid to tell Brett after everything her roommate has been through recently.
Brett inevitably learns and is upset at Foster for not telling her the truth. She eventually comes around and goes to support Foster during the interview with the Northwestern admissions committee.
Brett also learns Scott and Amelia are moving back to Rockford and is saddened, having imagined her half-sister growing up nearby.
Kidd's Girls on Fire program is going great, but she worries when Kylie, one of her high school trainees, stops showing up.
Gallo and Violet break up after Gallo becomes too clingy and proposes marriage.