On Christmas Eve, Dr. Carter pulls off a miracle when he revives an 18-year-old boy who's been flat-lined for over 30 minutes. However, when it is discovered that the boy is brain dead, his mother refuses to give up hope that her son will be fine. When another teenager with the same rare blood type comes into the ER in need of a liver transplant, Carter attempts to salvage the Christmas miracle. Meanwhile, a cranky old man in an elf suit tests Dr. Greene's patience. Dr. Benton's plans to spend Christmas Eve with his son are hampered by Dr. Romano, who dumps his workload on him so that he can attend a hospital function with Dr. Corday.