J.D.'s older brother, Dan Dorian, has come to town for a short visit. Within the first few minutes of his visit, he manages to piss off Dr. Cox and to pretend he's a doctor by giving a patient a diagnosis. Dan starts to hint that he's attracted to Elliot, which doesn't sit well with J.D., who lets him know that he and Elliot previously slept together, so she is off limits. Elliot later joins J.D. and Dan for lunch. Dan tries to pump Elliot for information about how J.D. is in bed. She insinuates that it was good, but not great. J.D. is shocked.
Dan tells Elliot that he tends bar and lives with his mother in her home, things that J.D. tries to make seem better than they actually are. Contrary to the enthusiasm J.D. shows for his brother, he's actually ashamed of how little he has accomplished in his life.
Noticing the tension between the brothers, Elliot urges J.D. to have a talk with Dan. She even gets the two of them together. Dan confronts J.D. about the fact that J.D. is embarrassed by how Dan lives his life. Later that day, the two of them finally get things out in the open. J.D. tells Dan that the reason his life is stuck in a dead-end job and why he still lives at home is that he's afraid to fail. Dan responds by walking away.
Meanwhile, Turk and Dr. Cox argue over the best course of treatment for Mr. Carney, a patient. Turk wins, so he ends up having surgery. He and Dr. Cox bet $20 whether he would survive the surgery. Previously, one of Turk's other patients had died. Feeling guilty about betting on Mr. Carney's life, Turk tries to make amends by going to his funeral, bringing Carla with him. It doesn't really make him feel any better. Dr. Cox later tells him that keeping their distance from patients and their families when they die is the only way to keep going.
J.D. and Turk end up at a bar, wearing the pig heads, one of their better Halloween costumes.