J.D. fears being contaminated with Hepatitis B. after a needle accidentally sticks his forearm. From then on, he tries to avoid any contagious patient, trading one of them with Dr. Cox. When the results are out and J.D. is clean, he tries to make up for his foolishness by spending some time with the contagious patient out of his own free will. Meanwhile, Elliot has a hard time combining her new relationship and keeping up with studies and chooses her studies over him. And Turk obsesses about getting in shape after Carla makes a fat joke about him.