Callie makes a decision about her relationship; the doctors receive devastating news.

Derek and Meredith adjust to life at home with their newborn; Arizona tries to repair her marriage; Jackson and Owen clash over financial issues.

The hospital gets inundated with flu infected patients, which causes the doctors to slowly fall ill one by one. Derek must fight off the sickness as he prepares to give a speech on brain mapping and the residents place bets on who will fall ill first. Meanwhile, a new doctor at the hospital gives Alex a glimpse into an alternate form of medical practice.

Cristina enlists Meredith to help her prepare an acceptance speech for her possible Harper Avery win and while Owen offers to attend the ceremony with her, she insists on going alone. Meanwhile, Derek feels overwhelmed between his responsibilities at home and at the hospital. April and Jackson come to a disagreement on children and religion, and Callie and Arizona try to reconnect in their marriage.

A familiar face returns to Grey Sloan, throwing many of the doctors for a loop. With Catherine putting on the pressure, Bailey has to make a decision about Alex while a tough ER case makes Amelia’s bad day even worse.