It's Christmas in the ER again. Luka and Abby as Rudolph and his elf, visit pediatrics, while Morris learns the meaning of Christmas when he plays Santa to a special girl. Ames takes action that creates tension between Luka and Abby, leading Luka to make a heartfelt confession. Teller returns, sending Gates and Ray on a mission, while Neela oversees an unusual kidney transplant case. Sam and Ben take a stand when a patient is dumped in an alley by Mercy Hospital. Morris, after getting a visit from one of his children, gets an offer he can't refuse, but somehow, does.