When a teenage pupil disappears after a school trip, Sarah Blane, her English teacher, in Fruin High in the west of Scotland, is horribly reminded of the time twenty-five years before, when her sister Ruth disappeared in similar circumstances in Edinburgh. And when Rubina is found murdered, Sarah has to confront the possibility that her sister may also have met a violent end, and her long-held belief that Ruth is still alive somewhere is seriously questioned. Mark Mckenzie, an investigative journalist, persuades Sarah to look into Ruth's disappearance in Edinburgh all these years ago, and the mystery of who killed Rubina and what might have happened to Ruth are explored simultaneously. Step by step both mysteries unfold until they reach their dramatic conclusion.