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.

Clare Cassidy is no stranger to murder. A high school English teacher specializing in the Gothic writer R. M. Holland, she teaches a course on it every year. But when one of Clare’s colleagues and closest friends is found dead, with a line from R. M. Holland’s most famous story, “The Stranger”, left by her body, Clare is horrified to see her life collide with the story lines of her favorite literature.

"So I thought I might take up paragliding. You know, buy one on eBay and just jump off the cliff one morning." Emily Willows is middle-aged, widowed, wealthy, and bored. When she makes those flippant remarks to her son over coffee one Friday, she has no inkling that within a few hours she will be facing the most terrifying situation of her life.

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.