Following an injury in the aftermath of an industrial fire, Severide and Seager work together to investigate an anonymous tip. Kidd searches for the right person to fill the open spot on Truck 81. A possible new recruit to 51 gets tested at a call.

The boys find out that the joys of playing Airsoft come with the challenges of dealing with teenagers.

After returning home from a visit for their parent's vow renewal, Bart and Nora quickly realize that things are not exactly as they left them. The duo race to repair any fissures in the timeline and restore everything back to the way it is supposed to be.

Jimmy asks The Roots to improvise songs about audience members on the spot in a new Freestylin’ with The Roots, then catches up with Samuel L. Jackson and Rupert Grint and welcomes musical guest Wet Leg.