In the village of Cronchie, a wealthy family are found brutally murdered. The Devil Stone, an heirloom rumoured to bring death if removed from their home, is the only thing stolen. The key suspects are known satanists. But when the investigating officer disappears, DCI Christine Caplan is pulled in to investigate. Caplan knows she is being punished for a minor misdemeanour when she is seconded to the Highlands, but she's confident she can quickly solve the murders and return home to her fractious family. But as she closes in on the truth, it is suddenly her life that is in danger.

Was the biggest case of his career the worst mistake he ever made? Ten years ago, DCI Jack Logan stopped the serial child-killer dubbed "Mister Whisper", earning himself a commendation, a drinking problem, and a broken marriage in the process...When another child disappears a hundred miles north in the Highlands, Jack is sent to lead the investigation and bring the boy home. But as similarities between the two cases grow, could it be that Jack caught the wrong man all those years ago?

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.

DS Rakesh Siyal is an idealist. Frustrated as an Edinburgh human rights lawyer, he joins the police, determined to solve the problems he sees with the criminal justice system from the inside, rather than out. His first day as a cop sees him sent down to Galashiels in the Scottish Borders, where he’s given a simple task – return a suspect to Glasgow to face justice.

Christmas 1979. Former TV reporter Adam Bailey is invited by his old flame, Harriet, and her husband, Sir Anthony, to Mulgrave Castle for the festivities. He reluctantly accepts, intrigued by their request for him to investigate the family curse. But within hours of arriving, a blizzard rolls in that leaves the castle and its guests stranded. And when one of the visitors is murdered, Adam and Harriet's sister, Eve, set out to solve the crime. But with danger stalking their every move, they must work fast to uncover the mystery before more lives are lost.