City of Mercy

"City of Mercy" is the twelvth Christmas episode of the NBC series ER, aired in the show's thirteenth season.

Synopsis
Ames takes action that creates tension between Luka and Abby. Teller returns, sending Gates and Ray on a mission. Neela oversees an unusual kidney transplant case. Sam and Ben take a stand when a patient from Mercy Hospital ends up at County. Morris learns the true meaning of Christmas when he plays Santa to a special girl.