Silent Night, Deadly Night

On Christmas Eve, a man dressed as Santa Claus stops Billy Chapman's car on a remote road and murders Billy's parents in front of him. The killer is implied to be Charlie, a janitor at Billy's grandfather's care home. Billy survives, and the killer is later revealed to be Charlie, who is fatally stabbed by Billy's mother.

In the aftermath, Charlie is revealed as the killer and is fatally stabbed by Billy's mother. Billy experiences a physical contact with Charlie, and an electrical surge passes between them, marking a traumatic awakening.

Years pass as Billy leads a transient life, drifting between towns and avoiding lasting relationships. Each Christmas, he begins to hear Charlie's disembodied voice urging him to punish the 'naughty' and guiding him via an Advent calendar ritual. He starts committing killings while wearing a Santa Claus costume.

Having killed a Christmas tree grower at a motel, Billy arrives in Hackett just before Christmas and takes a job at Mr. Sims's gift shop. He meets Sims's daughter Pam Sims, and the two start a relationship. The Advent calendar ritual continues to push him toward new killings.

As the Advent calendar counts down, Billy's killings escalate, including an attack at a secret neo-Nazi Christmas party. The spree draws attention as residents talk about missing children and a suspected abductor called 'the Snatcher.' Pam grows uneasy about Billy's proximity to the crimes.

Max Benedict, Pam's ex-boyfriend and a state trooper, grows suspicious of Billy as he investigates the disappearances. Reports spread about missing children and a suspected abductor known as 'the Snatcher.'

During the investigation, the Snatcher abducts a child and Pam's father is murdered on camera. The town reels as the link between the disappearances and the murders becomes clear. Pam resolves to seek retribution.

On the way to the Snatcher's location, Billy confides in Pam about his childhood trauma: the electrical surge when he touched Charlie and the guiding voice. He explains that the voice has directed him toward the crimes of anyone 'naughty.' Pam accepts his story and agrees to continue with him.

Inside the Christmas tree farm, they discover three abducted and drugged children hidden in an underground ball pit. Pam is captured by the Snatcher and dragged into the pit. Billy, guided by Charlie, pursues and confronts the Snatcher.

Billy defeats the Snatcher with a boxcutter but is stabbed during the struggle and seriously wounded. Max arrives at the scene and fatally shoots Billy. The death scene intertwines with Billy's final, psychic connection to Pam.

As Billy dies, he reaches for Pam's hand and an electric current passes between them, causing Pam to lose consciousness. She awakens later with Max and discovers flashbacks that reveal his involvement in the abduction. Pam attacks Max and kills him with Billy's axe.

With Max dead, Pam hears Billy's voice in her head, asking if she's 'ready for this,' and she grins, embracing the violent destiny suggested by Billy's bond. The ending hints that Pam may carry on Billy's legacy, continuing the cycle of violence.