An unemployed ex-coal miner becomes a recluse, obsessed with breeding butterflies in the garden of his home in a mining village near Edinburgh. His teenage son attempts to win his attention.

A zombie apocalypse threatens the sleepy town of Little Haven—at Christmas—forcing Anna and her friends to fight, slash, and sing their way to survival. In a desperate race to reach their loved ones, they soon learn that no one is safe in this new world, and with civilization falling apart around them, the only people they can truly rely on are each other.