Herrmann works on becoming a better man after Cindy's cancer journey. Kidd bonds with a homeless victim on a call. Kylie takes her firefighter exams. A harrowing call takes a toll on Brett.

Chicago's first responders unite in the wake of a catastrophic gas explosion and fire that threaten a city government building. Herrmann reluctantly shadows Pascal while Violet, Novak and Dr. Frost take charge of triage efforts on site.

The crossover continues on Chicago Med S10E11 In the Trenches (II) and Chicago P.D. S12E11 In the Trenches (III).

With the crew stretched thin, a performance efficiency expert evaluates Firehouse 51. Kidd and Severide bond with the mother of the baby they hope to adopt.