Ruth and Simon reluctantly agree to let their young teenage daughter, Heather, go off on a camping holiday in Cornwall with her best friend, Kelly, and her family. While on a vacation of their own, they get the news that both girls have gone missing. Kelly is found alive, but, after several days of searching, Heathers body is discovered inside some old mine workings. Although the police detective leading the investigation harbours suspicions of foul play, the verdict is that the death was accidental. The emotional strain of Heathers death ruins Ruth and Simons marriage. After the divorce, Ruth moves from London to Cambridgeshire, where she remarries and has another child -- a daughter, Beatrice. But when Beatrice is close to the age Heather was when she died, she too mysteriously disappears .
