In this brilliant debut, a psychologist finds herself drawn into the dark world of a serial killer - who may be closer than she thinks.... Ray and Marie Benson killed 13 women before they were caught, tried and imprisoned. Five of their victims were never found. Six years later psychologist Alice Quentin discovers a woman's body on the waste ground at Crossbones Yard. The wounds are horrifyingly similar to the Bensons' signature style.

Meet Zoe Finch, West Midlands Police's newest Detective Inspector. She's outspoken, ambitious, and damaged. And she's working a case that could make her career, or cost her everything...Fresh from the success of the Canary investigation into depravity and corruption at the highest levels, she's attracted attention. Not least from Assistant Chief Constable Bryn Jackson. But when Jackson is brutally murdered on the night of his retirement party, Zoe is dragged into a case that's deeply personal.

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.

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.

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.