To help Bailey become the best general surgeon at Seattle Grace, the Chief gives her new power, new responsibility, and the challenge of removing a young girl's inoperable tumor, as the new head of trauma, Owen Hunt, challenges both the attending doctor's methods and the residents' surgical abilities.

One of Meredith's oldest friends, Sadie, becomes an intern at Seattle Grace, but Mer's friends are less-than-welcoming to her; Lexie leads her fellow interns in secretive, unorthodox surgical training sessions; and a new surgeon, Virginia Dixon, brings rules and order to the OR.