Cristina scrubs in on the rare "humpty dumpty" surgery, much to the envy of her fellow doctors. Bailey wants to scrub in and writes her name on the surgical board as the resident in charge. Cristina erases Bailey's name in order to cover for Burke's hand tremor, which leads Bailey to believe that he was the one responsible for the deletion, leading her to question her talent for surgery and becoming discouraged. Derek receives a surprise visit from his sister and learns that she had slept with Mark, something that threatens their fragile friendship. George and Addison work with a pregnant woman with an unusual dilemma. Mark takes Alex off plastics after he chooses Addison's patient over being on hold at the DMV for Mark, but he later witnesses Mark and Callie discussing their one-night stand. Izzie returns to work, but is on probation and is not allowed to talk to patients, perform any surgery, or even go into an operating room. Bailey directs Meredith to be Izzie's boss for the day and the two treat a patient that may need to be admitted into psychiatry. At the end of the episode, Bailey witnesses Cristina reorganizing the operations board, and becomes suspicious.