On Christmas Eve, in the woods of Christmastown, California, a woman is violently disemboweled by a man dressed as a pirate, setting a chilling tone for what follows. A couple drives to a field that Tommy "Oneshoe" McGroo, Michael Hill, is said to haunt—this is where Boom Boom claims McGroo buries the people who bullied him when he was growing up. Boom Boom explains to his girlfriend Kitty the origin of the nickname Oneshoe: it started when one of his shoes was stolen and his family’s poverty left him unable to replace it. To compound the legend, he received an eyepatch adorned with a Christmas tree instead of a proper pair of shoes, a gift that fed his obsession with pirates and pushed him toward murderous fury. In a brutal sequence, McGroo’s vendetta turns physical as Boom Boom is forced to urinate in the field; McGroo rips off his testicles and then wounds Kitty. The violence escalates further when McGroo murders a man who is having kinky sex with his blindfolded wife, then rapes the wife himself, a stark display of the predator’s control.
At Lame Dog Hollow Camp, the survivors and former classmates—led by Ernie Cunningham, D.J. Vivona—are summoned to assemble a plan to confront McGroo when he inevitably comes looking for them. The group tries to fill the days with small amusements while they wait, including Isaac Hiltzik, an earnest amateur guitarist who only talks in song, and his girlfriend Lana Hooper, who head toward a nearby lake as danger quietly builds around them. McGroo does not wait long to strike; he crosses the distance to the couple and stabs them, continuing his method of silent, predatory killings.
The chill deepens as Dorcas Cunningham, Jason Christ, is the next target. He approaches with a running chainsaw, catching Dorcas by surprise, and the killing occurs in a way that highlights his stealth—Dorcas is only noticed after he steps on a twig, betraying the quiet of the night. The terror continues when Abby Honeydew is stabbed while looking for missing friends, amplifying the sense that no one is safe from McGroo’s reach. In a bid to face the threat, Ernie and Danny attempt to summon McGroo’s past victims with a Ouija board, but the plan is interrupted by danger; Ernie is killed with a screwdriver while walking through a cemetery.
Danny confronts McGroo in a direct fight, and during their struggle, he drives a rail spike into McGroo’s head. The monstrous figure survives the blow, responds with a fatal shotgun blast to Danny, and retrieves one of Danny’s shoes, a small, grim trophy in a battle where the killer seems almost supernaturally resilient. The clash leaves the group fractured and the camp's memory of the events haunted by what McGroo has already done and what he might do again.
Five years pass, and McGroo remains a fearsome constant in the lives of those who remember him. He appears older but no less relentless, having married the woman he once attacked and fathered a son. In a shocking final twist, the eyepatch McGroo once wore becomes a Christmas gift, passed down to his son—a disturbing symbol of a cycle that has continued to echo through the years, and a stark reminder that some legends, once born, refuse to die.
