Brad and Abby Cairn seem to have it all: a happy marriage, a spacious Manhattan apartment, a gifted nine-year-old son and a new arrival on the way. But young Joshua's resentment toward his baby sister triggers a series of tragic events that fill the Cairn household with utter despair and unspeakable horror. Is it all a series of eerie coincidences-- or the calculated agenda of a sinister sibling with the perfect plan for revenge?