Detective Inspector Munro is a burly Scottish policeman who doesn’t suffer fools gladly. Detective Sergeant West is an intelligent young woman, new to the force, with a lot to prove. When a missing person case lands on their desks, Munro is skeptical there is much to it. But their investigation soon comes to some strange findings, and before long a body is found. With a serial killer on their hands, they must act fast to trace a woman placed at the scene of the crime. Yet discovering her true identity, let alone finding her, proves difficult. And as the plot thickens they realise the crime is far graver than either of them could have imagined.

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.

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.

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?

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.