Ida loses her job and her parents in the space of a few weeks and, thrown completely off course, she sets off to Wales to the house her father has left her. But Heather, the young woman still in her teens whose home it was, keeps the house as a shrine to her late mother and is determined to scare Ida away. The two girls battle with suspicion and fear before discovering that the secrets harboured by their thoughtless parents have grown rotten with time, and that any ghosts Ty'r Cwmwl harbours are of their own making.
