The night before Christmas, a zombie apocalypse threatens the sleepy town of Little Haven. Anna and her friends must fight, slash and sing their way to survival, facing hellish snowmen, an undead santa and bloodthirsty elves in a desperate race to reach their loved ones hiding out at their local high school. But the lucky few that make it find out that the human threat they face there is the most terrifying of all... With civilisation falling apart around them, the only people they can truly rely on are each other.