Two families celebrating the Christmas holidays in a remote cottage face an unexplained nightmare when their young children suddenly turn into vicious killers, in a chilling horror from director Tom Shankland (WAZ). The prospect of having to kill your own offspring is the distressing theme of this highly suspenseful tale, which cleverly stages its shocks in broad daylight for maximum psychological dread. It borrows from Village of the Damned and Don't Look Now, and wrings epic tension from close-up moments and small details, particularly with the use of the visual motifs of blood and snow. The main shudders emanate from the cold way the kids go about their gory business with an odd mix of innocence and malevolence. Terrific performances give weight to the life-or-death dilemmas, with Hannah Tointon superb as the moody teen blamed for leading the younger kids astray by the uncomprehending adults.

A relaxing Christmas vacation turns into a terrifying fight for survival as the children begin to turn on their parents.