When Gareth Maloney walks into Jo's bookshop in the sleepy Scottish town of Banktoun, the life she thought she'd rebuilt starts to unravel. Because Jo recognises this man. The man who attacked her and her friend Claire, all those years ago, leaving Claire paralysed, and Jo tortured by the memories, unable to forgive herself for what happened. A desperate Jo turns to her friend, local policeman, Sergeant Davie Gray. The man she met after the attack. The kind, caring man who had vowed to look out for her since her mother's death. But he doesn't believe her.

As Acting DC Scott Cullen works with DC Craig Hunter to track down a witness who didn’t show during a court case, they stumble upon another crime–two homeless women, dying of a suspected heroin overdose. As they investigate, they uncover a far-reaching criminal empire, dealing death and misery to Edinburgh’s underclass. And come across another investigative team who may not be exactly on the same side. As the case brings two cops together and drives a wedge between another pair, can Cullen and Hunter rescue the witness and bring her assailant to justice?

I’ve been married to my kind, loving husband Lachlan for over twenty years. He’s my everything. We have two teenage children, a beautiful home and I feel so lucky to live this perfect life. Until my best friend says something that makes me doubt everything… She whispers it’s strange Lachlan has lived nearby to two unsolved murder cases. First, the murder of the woman in the small, Scottish village where he grew up and more recently the shocking death of a woman who lived round the corner from us. The thought makes my head spin. It’s just a coincidence, surely?

In the Scottish Highlands where secrets settle like mist in the glens, Detective Inspector James Corstorphine is summoned to a macabre scene–a gamekeeper hanging from an ancient oak, ensnared by an intricate trap of wire and bone. Still grieving his wife's death, Corstorphine finds himself hunting a killer who crafts elaborate deathtraps from human remains–clockwork mechanisms that deliver murder with chilling precision.

Met cop DI Rob Marshall is hot on the trail of the serial killer known as the Chameleon, who has abducted, tortured and killed a series of young women in Northwest London. As they close in, the Chameleon—who switches identity to get close to his victims—shoots Marshall’s partner and escapes.