Two men involved in a car accident arrive at the er by ambulance. Chen administers to one of them, Terry Waters (MITCH PILEGGI - "The X-Files"), a belligerent 46-year-old. Waters' daughter arrives and discusses with Chen personality changes her father has recently undergone. Later, Chen diagnoses him with Huntington's disease, a progressive neurological disorder--a genetic disease. But Waters refuses to disclose the illness to his daughter even though she might also harbor the disease.

A kidney becomes available for transplant, and Kovac preps a patient. But tests reveal the man suffers from unstable angina. The next candidate arrives at the hospital and discovers she's 8-weeks pregnant. Since she chooses to keep the baby, she can't have the transplant. A third candidate tests positive for cocaine. While Kovac waits for a fourth candidate, Corday takes the cocaine user upstairs for surgery out of fear that the kidney will be damaged if surgery gets delayed.

Weaver treats a severely retarded, 14-year-old girl with San Filippo Syndrome who can't even feed herself. Her foster mother does not have the authority to give Weaver permission to do the necessary procedure. Romano believes Weaver is simply prolonging the girl's life and forbids her from performing it. Weaver defies him and Romano suspends her.

David Greene expresses a desire to move out on his own. A prescription mix-up almost kills a patient. And Kovac barbecues dinner at Hathaway's house--during a snowstorm.