Grace, a soon-to-be stepmother, is left in charge of her fiance’s children, Aidan and Mia, when their father abruptly leaves their remote holiday home for work. Snowed in by a blizzard and cut off from the outside world, the three are forced to spend time together in the isolated lodge. As their uneasy relationship begins to soften, strange and frightening events stir up shadows from Grace’s dark past.