Detective Constable Angus MacVicar has just landed his dream job – transferred out of uniform and assigned to Oldcastle’s biggest ongoing murder investigation: Operation Telegram, hunting the “Fortnight Killer”. Every two weeks another couple is targeted. One victim is left at the scene, their corpse used as a twisted message board. The second body is never seen again. This should be the perfect chance for Angus to prove himself, but instead of working on the investigation’s front line, he’s lumbered with the forensic psychologist from hell.

Welcome to the Misfit Mob... It's where Police Scotland dumps the officers it can't get rid of but wants to: the outcasts, the troublemakers, the compromised. Officers like DC Callum MacGregor, lumbered with all the boring go-nowhere cases. So when an ancient mummy turns up at the Oldcastle tip, it's his job to find out which museum it's been stolen from. But then Callum uncovers links between his ancient corpse and three missing young men, and life starts to get a lot more interesting.

Five years ago his daughter, Rebecca, went missing on the eve of her 13th birthday. A year later the first card arrived: homemade, with a Polaroid picture stuck to the front – Rebecca, strapped to a chair, gagged and terrified. Every year another card: each one worse than the last. The tabloids call him The Birthday Boy. He’s been snatching girls for 12 years, always in the run-up to their 13th birthday, sending the families his homemade cards showing their daughters being slowly tortured to death.

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.

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?