Arthur "Artie" Plum is a down-on-his-luck, cynical conman deeply in debt to the local mob. His "big idea" to save his life? The "North Pole Heist." Artie lands a job as the Santa Claus at a high-end luxury mall on Christmas Eve, not to spread joy, but to gain access to the ventilation ducts that lead to the jewelry store vault next door.
He isn't alone. His partner is Barnaby, a brilliant but grumpy locksmith who, due to his short stature, is forced to humiliate himself by wearing the "Head Elf" costume to maintain their cover. The muscle of the operation is "Reindeer," a mute, unpredictable ex-convict serving as the getaway driver and enforcer, nicknamed for a grotesque tattoo of antlers on his neck. Artie's perfect plan begins to crumble when he inadvertently becomes a father figure to an abandoned kid in the mall, and the security team starts to suspect that Santa smells like cheap whiskey and gunpowder.
