There's a serial killer targeting the streets of Newcastle, seemingly picking his victims at random but subjecting them all to the same torturous end. When the Chief Inspector on the case goes missing, it falls on DCI Ryan to track down the man who is brutally murdering women and goading the police to 'catch me if you can'. As everyone becomes a suspect, Ryan and his team get drawn further and further into the case, but for Ryan the nightmare gets closer to home than he could ever have imagined.

When the chief suspect in the notorious Peek-a-boo 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 Peek-a-boo fashion, Bone is persuaded to return to lead the new investigation. But as Bone and his team hunt a copycat killer, and with time running out before yet another cop is slain, Bone’s terrifying past returns to tear open old wounds and push him to very edge of the abyss.

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.

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?