Summoned in the early hours of the morning to a Glasgow flat, forensic scientist Rhona MacLeod is confronted by a horrific crime scene. A teenage boy has been found mutilated and strangled to death by a vicious killer. But her grim task of scanning for evidence is made even more unsettling than normal by the boy’s remarkable resemblance to her – and by the fact that she gave up a baby boy for adoption 17 years ago. Overcome by guilt, Rhona sets out to find the boy’s killer and establish whether the young victim is her long-lost son.

The village of Blackrig in the Scottish Highlands was shocked when seventeen-year-old Ailsa Cummings went missing five years ago. While a recent pandemic has stirred up old tensions and sparked an animosity in the small community towards outsiders. Angry that the local estate is to reopen its luxury ‘party house’ to tourists results in an angry mob causing damage to the property’s hot tub, only to unearth the buried body of the missing girl in its foundations. The discovery ignites old suspicions among the villagers, especially the men, who’d known Ailsa.

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.

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.