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 the chief suspect in the notorious "peekaboo cop killer" case blew himself up, almost taking lead investigator DCI  Duncan Bone with him, the psychologically damaged detective thought his days on the force were over. But, when another PC is abducted and murdered in the same deranged peekaboo fashion, Bone is persuaded to return to lead the new investigation.

When a 15-year-old girl fails to make it home after school, DI Heather Filson believes she’s dealing with just another teenage runaway. The girl’s grandfather, a notorious Glasgow gangster, disagrees. Convinced one of his underworld enemies has grabbed her, he’s prepared to bathe the city in blood in order to bring his princess home.

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.

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?

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.

Detective Inspector Fenella Sallow is obsessive about her work and driven by her own demons. When the body of a retired artist is discovered atop the blackened embers of the town bonfire, the community is rocked to the core. It falls to DI Fenella Sallow and her team to find out how she came to be there. In her 50s, the veteran detective inspector thought she had seen it all. But behind the curtained windows and closed doors of the idyllic Cumbria coastal setting lurks pure evil.

The head of Scotland’s most powerful crime family is brutally murdered, his body dumped inside an ancient grave in a remote cemetery. Detectives Max Craigie and Janie Calder arrive at the scene, a small town where everyone has secrets to hide. They soon realise this murder is part of a blood feud between two Scottish families that stretches back to the 1800s. One thing’s for certain: it might be the latest killing, but it won’t be the last.

Detective Chief Inspector Harry Grimm is forced to take leave from Bristol’s Major Investigations Team when his boss, tired of Harry chasing the ghost of his murderous father, sends him north on secondment. Used to city life and high stress, Harry fears his life will now be spent handing out speeding tickets, finding lost sheep, and directing tourists. But when a local teenager runs away, Harry finds himself pulled into an investigation much worse than anyone could have ever expected.

For 16 years, the Midwinter Butcher has been lurking in the shadows, committing ritualistic animal killings on the anniversary of DI Joseph Stone's son's tragic death. And ever since, Joseph has been desperate to bring them to justice.