J.D. is called in to work on his day off and every time he tries to go home, he is pulled into another drama. Turk searches for a heart donor to save a dying patient; Carla is worried that she doesn't have the courage to become a parent. Meanwhile, Eliot doesn't think she has the brains to lead a question and answer session on a subject she knows little about. All the while the Janitor is trying to make the hospital easier to navigate by painting color-coded lines, including a yellow line, which leads to the exit.