Newly-married husband Mike could not understand why his pretty young wife Kirsten preferred the less habitable house of the two adjacent homes that the estate agent offered them. But Kirsten was afraid of the other house in spite of the excellent condition it was in, so Mike, very much in love, pandered to her inexplicable whim.

Kirsten's fears were not groundless, although by the time she and Mike realised the extent of the difficulties they found themselves in it was too late for both of them. The house next door was bought by another couple, Justin and Alexandra Blair. At first they seemed an ordinary pair, although Mike thought that Alexandra was quite the most beautiful woman he had ever seen. But as Kirsten got to know them better, she realised that they were not the same as other people and that they were capable of achieving feats of extraordinary power.

When Justin offered to change Kirsten's life by helping her to conceive the child she thought she would never be able to have, she seized the opportunity gratefully and tried to ignore the fact that she was entering into a contract with the devil...