Wildfires threaten the Seattle region, leading to a flood of patients and emergency procedures. The doctors juggle overcapacity in the ER, complex surgeries and personal stress. Meanwhile, Meredith makes a rash decision that can't be undone.

Meredith and Amelia prepare a funding proposal for their Alzheimer’s research. Meanwhile, Teddy and Owen hit a breaking point in their marriage, while Jules has an awkward encounter with Dr. Beltran.

Amelia and Simone attempt to perform a high-stakes and groundbreaking brain surgery. Teddy and Bailey attend a medical conference and run into Dr. Cass Beckman. Meanwhile, Jo struggles with her irritation toward a younger OB-GYN.