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.

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.

Ailsa Connolly was a brilliant psychologist and a respected criminologist. She was also a serial killer. Six years ago, DCI Sean Bracken caught her just before he was about to become her seventh victim. Every year on the anniversary of her incarceration, she taunts him with a phone call, giving him one message: "When I get out, I'll kill you." Now, Bracken has transferred back to Edinburgh and is thrown into the deep end on his first day back on duty. There's a killer who is emulating Ailsa, threatening to surpass her body count.

Former soldier. Ex-copper. Current man on the edge. Shunned by his old colleagues, and dividing his time between a dead-end job and the bottom of a whisky bottle, former Police Scotland detective superintendent Bob Hoon’s life is a mess. Then an old face from Hoon’s Special Forces days turns up asking for help: His teenage daughter has been missing for months, the police have drawn a blank, and he needs the kind of help that only Hoon can provide. And besides, Hoon owes him one.

The head of Scotland’s most powerful crime family is brutally murdered, his body dumped inside an ancient grave in a remote cemetery. Detectives Max Craigie and Janie Calder arrive at the scene, a small town where everyone has secrets to hide. They soon realise this murder is part of a blood feud between two Scottish families that stretches back to the 1800s. One thing’s for certain: it might be the latest killing, but it won’t be the last.