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?

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.

It's DS Logan McRae's first day back on the job after a year off on the sick, and it couldn't get much worse. Three-year-old David Reid's body is discovered in a ditch: strangled, mutilated and a long time dead. And he's only the first. There's a serial killer stalking the Granite City, and the local media are baying for blood. Soon the dead are piling up in the morgue almost as fast as the snow on the streets, and Logan knows time is running out. More children are going missing. More are going to die.

After an elite criminal profiling unit is shut down amid a storm of scandal and mismanagement, only one person emerges unscathed. Forensic psychiatrist Doctor Alexander Gregory has a reputation for being able to step inside the darkest minds to uncover whatever secrets lie hidden there, and soon enough he finds himself drawn into the murky world of murder investigation. In the beautiful hills of County Mayo, Ireland, a killer is on the loose. Panic has a stranglehold on its rural community, and the Garda are running out of time.