Something strange is happening to Tom Nelson's world this Christmas. Or maybe it was always like this, and he just hadn't noticed. The holiday season has come at just the wrong moment in his career, and his personal life. Pressures are rising, deadlines are moved forward to clear Christmas, more and more people are putting unreasonable demands on his time, his money, his very life. And yet at the same time, the normal functioning of the world seems to have been suspended - nobody is answering their phones, nothing is getting done, everything takes twice as long, and nothing seems to work properly anymore.

Everyone around him seems bent on causing problems and tensions, and at the source of every upset in his life can be traced directly back to the ominous shadow of the festive season.

As the pressures become unbearable, Tom makes commits a crime so heinous that it will turn his world inside out, and reduce him to an outcast in the eyes of his family, work colleagues and friends - He makes the decision to opt out of Christmas.

At first, the people around him refuse outright to take him seriously. When they eventually begin to, their attitudes change. Suddenly, they are cold, distant.

Meanwhile, after an outburst in a shopping centre, Tom is approached secretly by Carrie who introduces him to an underground group of anti-Christmas individuals. Each with their own story to tell, and their own slightly disconcerting idiosyncrasies. Tom is not at all sure he belongs with this group of oddballs, but he finds himself drawn to Carrie.

Back in the real world, the people around him have turned distinctly nasty. His rejection of their time of joy has isolated him. Friends and family advise him to seek therapy. He can't work out why - he hasn't changed- everyone else has. As Christmas looms and the shopping centres fill with increasingly desperate people, working themselves into a frenzy, his life begins to dissolve. His wife - left to deal with the growing battle between their two families leaves him, taking the kids. He looses his job.

Tom increasingly feels as he walks the streets that people are behaving strangely - shop assistants and surveillance cameras seem to be watching him. The population appear to have turned into robots - their personalities, and free wills temporarily subverted by the festive season. Father Christmas seems to be following wherever he goes. He wonders if his mind really is being affected, and only Carrie seems to understand.

Tom makes up his mind to tell her how he feels about her, but as he is about to, she vanishes. It appears that she is simply bustled away in a crowd of Christmas shoppers, but he suspects something more sinister. He believes he sees her being dragged into Santa's Grotto in a large department store.

Tom confides his fears to some of his anti-Christmas group - most advise him to simply keep his head down until it is all over, but the most insane among them agree to form a rescue party.

They break into the shopping centre that night, and enter Santa's lair. They are amazed - The grotto leads down into a dark tinsel dripping cave system under the city. It sprawls out to link every grotto, every shop. Every security camera, every television station, every church is connected to this underground network...

Worse, this conspiracy theorist's nightmare is crawling with Elves, Santas, and other abominations. Once discovered, these monsters attack - one of the group is dragged away - the others just manage to make it out of the grotto.

Back in the real world, it is Christmas Eve. The zombification of the population is almost complete, fights are breaking out as families turn against each other in the general atmosphere of goodwill. It seems to Tom as though civilisation has collapsed. He and the survivors of his group are running out of places to hide.

Their only option is to return to the labyrinth - armed to the teeth, and ready to take out anything that tries to stop them. Gingerly, they venture into the grotto, and deeper into the dank, decorated maze, searching for whatever is at the centre. Every flash of white beard instils horror - every sound of sleigh bells triggers a volley of gunshots from the band of fighters.

They inflict many casualties upon the inhabitants of this world, but whenever one Santa is shot or cut down, two others emerge from the shadows to take his place. They appear to be merciless, and infinite in number. One by one, our heroes are picked off. Soon, only Tom remains - alone and scared in the darkness.

Eventually, he finds Carrie. She is imprisoned, connected to the walls of a cavern, and in the midst of a conversion process which has already begun to alter her mind. In the background, Jingle Bells plays hypnotically.

Quickly, he cuts her loose from the strangling tinsel, and drags her out, but the creatures of the labyrinth block their way, forcing them deeper and deeper into the maze.

They find themselves in the centre of the grotto where the tunnels open out into a large chamber. At the centre sits the massive form of "the Claus" - the king-pin of all the Santas, wired into the underground web, and bloated with greed and misery.

The couple manage to shoot their way out, pursued by this monster, and escape into the darkened streets. Christmas day is coming to an end by now, but the danger is far from over. As the only people who know the "true meaning" of Christmas, they cannot be allowed to escape.

They flee to an empty building to make their final stand, pursued by the elves, the Santas, and the survivors of the annual family carnage Christmas Day has inflicted on the possessed public.

As the night wears on, and the couple come to the end of their ammunition, the hastily erected barricades begin to fail. Finally, all is lost. The Claus moves in for the kill.

Miraculously, dawn suddenly breaks - light floods into the room. It is Boxing day! The Claus crumples to the floor. It's power draining. It's time passed for another year. It begins to dissolve.

The following day, the evidence is gone. People return to their lives - the surreal carnage of the previous weeks forgotten. After her partial conditioning, even Carrie remembers nothing of the ordeal: