Costumed patients create a challenge for the doctors; Derek and Ben work on a new surgical technique; Richard asks a resident to perform his next surgery, angering Bailey.

After an anonymous complaint is issued by one of their own, the hospital implements a non-fraternizing policy causing the couples to panic. Meanwhile, Emma and Owen talk about the future, Cristina and Meredith enjoy a little girl time, and Richard enlists the residents to help research a rare cancer case.

An earthquake shakes the ground at Grey Sloan Memorial Hospital, trapping Maggie in an elevator and threatening Meredith’s long streak of successful surgeries. Meanwhile, Owen gives medical advice to a child over the phone and Ben confides in Jackson.

A young boy is admitted to Grey Sloan Memorial and his case has a profound impact on the doctors. Meanwhile, April is faced with a surprising patient, and Jo continues to deal with her estranged husband.