In a harsh, chilling arc spanning a dozen years, the life of Billy Chapman unfolds around a single, repeating reminder: some holidays breed danger as deeply as they promise joy. In 1971, when Billy is just five, his family visits a Utah nursing home where his catatonic grandfather lives. After his parents leave the room, the old man suddenly wakes and whispers a terrifying warning: to fear Santa Claus, for Santa punishes the naughty. A few miles down the road, a criminal in a Santa suit—the Santa robber who had just robbed a liquor store and killed the owner—tries to carjack them. The father is shot and killed, and the mother is fatally slashed when she resists. Billy escapes, leaving his baby brother Ricky behind in the car, while the bloody chaos of that night marks him forever.
Three years later, in December 1974, Billy, now eight, and Ricky, four, are housed in an orphanage run by a stern Mother Superior who treats punishment as virtue and order as salvation. Sister Margaret, a kinder presence, secretly tries to help the boys, but Billy endures regular discipline. On a Christmas visit from a man in a Santa Claus suit, Billy is forced to sit on his lap and, in a moment of protective fury, punches the visitor before retreating to his room in stunned horror.
A decade passes, and by spring 1984 Billy is eighteen and has left the orphanage to pursue a normal life. He lands a job as a stock boy at a local toy store, supported by Sister Margaret, and he develops a crush on a coworker, Pamela, even as morbid visions of his parents’ murders keep intruding on his thoughts. The Christmas Eve shift thickens with dread when the store’s Santa Claus is injured, forcing Billy to step into the costume as his boss, Mr. Sims, orders him to take his place. The party after the store closes grows tense as Billy, still wearing the Santa suit, struggles with memory-induced despair while colleagues Andy and Pamela share a kiss in the back room.
The violence erupts when Billy follows them and witnesses Andy attempting to rape Pamela. His long-suppressed rage boils over as he hangs Andy with a string of Christmas lights and then kills Pamela with a box cutter. The slaughter continues as Billy murders Mr. Sims and his manager Mrs. Randall. Sister Margaret discovers the carnage and hurries to the police for help. Billy then breaks into a nearby house where Denise and Tommy are having sex while a little girl named Cindy sleeps upstairs; he impales Denise on a set of deer antlers and hurls Tommy through a window. When Cindy asks if she has been nice or naughty, she says nice, and Billy, in a cruel moment, hands her the box cutter he used earlier. He also sees bullies harassing two teenage boys and, in a brutal escalation, decapitates one of the bullies with his axe.
The next morning, Captain Richards and Sister Margaret realize that Billy is headed toward the orphanage where Ricky still lives. Officer Barnes is ordered to secure the area and, in a tragic misjudgment, kills a pastor in a Santa outfit named Father O'Brien, mistaking him for Billy. As Barnes continues patrolling, he is struck by Billy’s axe and falls. Billy confronts Mother Superior, now wheelchair-bound, and as Captain Richards shoots him in the back, Billy collapses. In his final moment, he tells the frightened children, “You’re safe now, Santa Claus is gone.” The disciples of fear are left with a chilling last image as Ricky, now 14, scowls at Mother Superior and coldly utters, Naughty.
> You're safe now, Santa Claus is gone
> Naughty.
