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.

Summoned in the early hours of the morning to a Glasgow flat, forensic scientist Rhona MacLeod is confronted by a horrific crime scene. A teenage boy has been found mutilated and strangled to death by a vicious killer. But her grim task of scanning for evidence is made even more unsettling than normal by the boy’s remarkable resemblance to her – and by the fact that she gave up a baby boy for adoption 17 years ago. Overcome by guilt, Rhona sets out to find the boy’s killer and establish whether the young victim is her long-lost son.

When a young boy discovers the body of a woman beneath a thick sheet of ice in a South London park, Detective Erika Foster is called in to lead the murder investigation. The victim, a beautiful young socialite, appeared to have the perfect life. Yet when Erika begins to dig deeper, she starts to connect the dots between the murder and the killings of three prostitutes, all found strangled, hands bound, and dumped in water around London.

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.

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?