It's Christmas Eve in the ER, and there's a new Chief of Emergency Medicine: Dr. Luka "Santa" Kovac, dispensing gifts and time off for honeymoon-bound Neela. Luka and Abby make plans for Christmas Day, but something is on Abby's mind. Kerry, Pratt and Abby treat a girl who is the victim of a random bullet fired by gang members, leading to a vigil outside the ER and a "scared straight" lesson, administered by Pratt, in the consequences of gun violence. Luka and Ray treat a woman with cancer who chooses quality time with her family over fighting the disease. Clemente's former flame arrives, and the fires re-ignite, despite his efforts to resist. When a testy Santa insults a group of blind children, Eve's extreme response forces Luka to bring in the nursing supervisor, and Eve is fired. Haleh auditions singers for the Christmas party and finds a surprising partner in Morris. Sam discovers the impact Steve's imprisonment has had on Alex, and takes him to visit his father. At the end of the day, the gang gathers for the annual Christmas party. Luka and Abby exchange gifts, and Abby shares some big news with Luka: she's pregnant!