The staff deal with a boy, who literally has become a tree; a patient who vocalizes all his thoughts aloud, no matter how rude; and a lung cancer patient, who ends up having sex with Alex in Joe's restrooms. Meanwhile, the Nazi is back with a vengeance from recent events, Burke's mother catches Cristina offering a new hospital service, Callie covers for Meredith, Izzie starts baking out of grief and Derek and Addison find their marriage is over.