100th episode. As a tribute to 'The Wizard of Oz', the four companions go on a similar journey. Turk needs a heart from a patient in order to be the first resident to assist performing an in-house heart transplant. Carla needs courage to have a child with turk even though she can't stand babies, Elliot needs the brains to handle speaking in a medical seminar, and J.D, well, he just wants to get home...