A frail piece of witchery sustains its fantasy of unborn twins taking possession of an English house damned by a hateful marriage. Janet and Trixy are called into being by their mother's desperate guilt of having been persuaded, by her determined mother, to have an abortion, and her terrible loneliness. Their growth of understanding of human ways, their ""poultry geese"" manifestations that create further tensions in the house, their dislike of their grandmother and the way in which they put an end to her meddling, their attempts to aid their mother which only add to the gossip about her -- these are the origins of the final tragedy. For the twins grow older, Janet's heart is given to a young artist whose perception of her dims when he falls in love with a real girl and Janet must have her revenge before she vanishes. The touch of the real and the unreal, the force of suppressed emotions and the clash of unhappy people give substance to what might have been only a supernatural tale. A nice sort of change.