D.I. Duncan McAdam is dispatched home to the Misty Isle. A body has been found buried in a remote location on the Waternish peninsula. Well-preserved in the peat, Isla Matheson—missing for the better part of two decades—is revealed to a shocked island community. A teenage runaway is dead...and no one is talking.

When a body is found on a lonely cliff top path, the angelic face of a murdered teenager lies facing the rising sun. Strangled by the hands of an unknown killer, it falls to DI Tom Janssen and his fledgling team to find out how she came to be there. Destined for a career in medicine, one to rival that of her parents, Holly Bettany’s future was as bright as it had been privileged. Seemingly, all that could threaten this promising teenager’s life was Holly herself.

Five years ago, DCI John Lomond led the search for notorious Glasgow child-killer ‘The Sandman', until personal tragedy forced him off the case. In Lomond's absence, the killer was never found. Now, with nothing but work left in his life, Lomond remains obsessed with the case–despite the nightmares it brings. When a child is abducted in similar Sandman fashion from an affluent Glasgow suburb, Lomond is brought in to find them before it's too late.

When Matt Ballard was starting out his career, three boys were murdered in the same area, the remote and bleak Gibbet Fen. When the main suspect was killed in a hit-and-run, the killings stopped. But Matt was not satisfied that the real murderer had been caught. Over 25 years later, Matt gets a photo in an unmarked envelope. It's of the Gibbet Fen crime scene. And the picture was taken before the murder took place. More photos arrive, relating to the historic murders, as well as intimate pictures of Matt's very secret private life.

Criminologist Martin Knight lives a gilded life and is a thorn in the side of the police. But then his wife, Liz, goes missing. There is no good explanation and no sign of Martin.... To make things worse, Liz is the ex-girlfriend of DCI Craig Gillard who is drawn into the investigation. Is it just a missing person or something worse? And what relevance do the events around the shocking Girl F case, so taken up by Knight, have to do with the present? The truth is darker than you could ever have imagined.