Christmas Eve finds Chen unable to locate someone to cover her shift. Because she needs to care for her dad, she quits. Pratt visits her house and tries to talk her out of euthanizing her dad, but she ends up doing it anyway. Carter and Wendall share an awkward kiss. New med student Jake and Abby treat a man with lupus and a family living in their car. Carter forces Ray to miss his plane. Morris's girlfriend visits.