Ruth and Simon Pierce's rare romantic break is shattered by devastating news: their daughter, Heather, on holiday in Cornwall with a friend's family, has disappeared. The loss is more than they - or their marriage - can bear. But time does heal and slowly Ruth builds a new life for herself. A new husband, Andrew - even a second daughter, Beatrice. The chances that history could repeat itself are next-to-impossible - that is until, years later, a desperate phone call launches DI Will Grayson and his partner, DS Helen Walker, into an investigation which will test their professional and emotional resources to the very limit.