The storm may have passed, but now the relationships and romance of Grey Sloan Memorial must survive in its wake. Bonds are tested, love is lost and the hospital bids farewell to Dr. Cristina Yang. Following a massive mudslide, the hospital becomes a madhouse, and the lives of two doctors hang in the balance. The drama escalates as Arizona tries desperately to mend her broken marriage, while Derek and Meredith juggle their roles as surgeons and new parents. Meanwhile, a stunning betrayal pits Cristina against Meredith and, as April prepares for her big day, a familiar face returns to town. Big secrets lead to big problems and turn best friends into rivals.