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.

After firing some of Grey Sloan's best, Catherine continues to interfere with Meredith and Amelia's research. Accidents at a climate change protest bring unique cases to the hospital, and Bailey encounters a blast from the past.

Meredith and Catherine continue to disagree, and Meredith confides in Bailey for support. Richard, Winston and Lucas spend the day outside of the hospital, and Blue deals with a relationship from his past. Levi meets the new hospital chaplain.

In the midst of a deadly heat wave, the team at Grey Sloan struggles to keep up with an overwhelming amount of patients. Amelia and Winston face a challenging surgery, while Jo and Lucas run an errand for the hospital that takes an unexpected turn.

The aftermath of the convenience store shooting brings chaos to Grey Sloan. Ben hits a wall with his new emergency preparedness plan. Romantic tensions surface for Owen, while Amelia and Winston disagree over the surgical plan for a young patient.

Following a difficult case, the team faces the complexities of medical ethics. Meanwhile, Bailey continues to navigate her working relationship with Ben, while a group of college students on a scavenger hunt causes chaos around the hospital.

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.