Sam Tiler, Christopher Allport has been struggling to recover from his encounter with Jack Frost last Christmas. To escape the mounting stress, his wife Anne Tiler, Eileen Seeley, suggests a tropical vacation to The Bahamas to attend the wedding of his deputy Joe, Chip Heller, and his fiancée Marla, Marsha Clark. Sam reluctantly agrees, hoping a warm break might steady his nerves and give him distance from the lingering, unsettling memories.
Meanwhile, the FBI uses antifreeze to dissolve Jack and test the remains for genetic material. An accident causes Jack to wake up, reform, and break free. Jack, now sharing a psychic link with Sam because Sam’s blood mixed with Jack in the antifreeze, begins to follow him everywhere, turning the vacation into a tense game of cat and snowman.
The travelers arrive to a greeting from the island’s eccentric Colonel Hickering, Ray Cooney, along with his assistants Captain Fun, Sean Patrick Murphy, and Bobby, Tai Bennett. Jack washes ashore and kills three women, casting a dark shadow over what should be a carefree getaway. The next morning, the Colonel discovers the bodies and tries to cover up the incident to protect his resort’s reputation. Yet the island’s security head, Agent Manners, David Allen Brooks, who had survived Jack’s maiming, suspects that Jack has returned and begins quietly connecting the dots.
As Jack’s rampage continues, he kills a beach model and her cameraman, escalating the dread. Sam grows suspicious when he crosses paths with Agent Manners, who proposes an uneasy alliance to stop Jack Frost. Sam teams up with Manners and Captain Fun, who is revealed to be Manners’ undercover assistant, in a risky plan to trap the killer. Their attempt backfires when the snowman they capture turns out to be Colonel Hickering in disguise, exposing the deception and deepening the peril.
The violence intensifies: after slaying another beach model, Jack freezes the resort into a snowy nightmare. Guests scramble into corridors and hallways to avoid the killer as a holiday gathering becomes a deadly arena. Sam, Anne, Marla, Manners, and Joe improvise a last-ditch defense, sealing themselves in a room and dousing the space with antifreeze to keep Jack at bay.
With the trap thwarted, Sam and Manners push forward to seek real help, eventually stumbling upon a room where the Colonel, Captain Fun, and Bobby have barricaded themselves. They manage to scrounge more antifreeze and lure Jack into a coolant pool, hoping the chemical weakness would do what the lab experiments could not. But Jack has grown tougher through his time in the laboratory and resists the cooling attack, spitting out a snowball before fleeing, with Manners in pursuit toward the woods.
From the safety of a shelter, the survivors watch in horror as a snowball boundary breaks and a baby snowman hatches, which then brutally kills Captain Fun. Meanwhile, Manners discovers a shed stacked with dozens of snowball offspring that eagerly descend upon him, tearing through his defenses. The group continues to improvise, trying to trap as many of the growing snowman army as possible while they wait for help to arrive by sea.
Anne realizes a bizarre vulnerability: bananas can kill Jack—and since Sam is allergic to bananas, this flaw could potentially be shared with the snowman threat. The revelation injects a new, if unsettling, glimmer of hope into the dying night. In a dramatic turn, Jack watches a baby snowman die and becomes enraged, escalating his assault by killing Bobby and Colonel Hickering. Marla and Joe flee and barricade themselves in the freezer with Captain Fun’s body, while Anne faces an onslaught from Jack.
In a final, desperate gambit, Sam fires an arrow tipped with a banana at Jack, triggering a fatal explosion that ends the villain’s immediate threat. Anne and Sam embrace, the danger seemingly past, as the island’s danger recedes with the away-vessel’s approach.
As credits roll, the two sailors aboard the supply boat are shown crushed by a giant carrot, a grim hint that Jack may still be alive. The postscript reveals that Joe and Marla were accidentally left in the freezer, a sobering reminder of the chaos that unfolded on the island.
