When a heat wave hits the city, Alex is appointed Trauma Team Leader as the hospital is faced with an influx of patients during a blackout. With no back-up power available, Dawn and Charlie must figure out a way to continue their surgery as Joel and Maggie attempt to keep a patient alive while stuck in an elevator.

Alex races to find an organ replacement; Joel helps a couple; Charlie is pushed to his breaking point.

Alex struggles with being a mom, a surgeon and now mentoring a junior resident.

Kristine shows up at the hospital with baby Luke's blanket.