Three days before Christmas, the dysfunctional Engel family come together for Christmas. Max remains a firm believer in Santa Claus, and intends on sending a letter to him. Amongst his family are his parents Tom and Sarah; his teenage sister Beth; his aunt Linda and uncle Howard; their children Howie Jr., Stevie, Jordan, and baby Chrissie; Sarah and Linda’s cantankerous aunt Dorothy; and Tom’s mother Omi (Omi means Gran in German), who speaks mostly in German.
Max wants to continue family traditions, but tension between his relatives leads to them losing their Christmas spirit. When his cousins read out his letter to Santa and mocks him for it, he tears up the letter and throws it out the window. That night, a severe blizzard engulfs the town, and causes a power outage. Beth ventures out to check on her boyfriend, but is chased by a large horned creature. She hides beneath a delivery truck, but the creature leaves a jack-in-the-box which attacks, presumably killing her.