Mary McIntyre's disappearance tore the local community apart, inflicting wounds that still prove raw for those who knew her.

So when the present-day discovery of a child's remains are found in a peat bog south of Glasgow, it seems the decades-old mystery may finally be solved.

Called in to excavate the body, forensic scientist Rhona MacLeod uses the advances made in forensic science since Mary's vanishing to determine what really happened all those years ago . . . and who was responsible.

One key person had been Karen Marshall who was devastated by her best friend's abduction. Questioned by the police at the time had led to a dead end and the case soon went cold.

Now the news of the discovered body brings the nightmares back. But added to that, memories long-buried by Karen are returning, memories that begin to reveal her role in her friend's disappearance and perhaps even the identity of the killer . . .