A brutal double murder on a Norfolk beach horrifies the town of Cromer. The way the victims died is chilling and so Norfolk’s Major Investigation Team task DS Ashley Knight to manage the case. It soon becomes clear that the murders were carefully planned and the finger of suspicion points to an organised crime gang, but as the evidence mounts, a far more sinister theory emerges.

When a woman's body is discovered in a cathedral and hours later a young man is found hanging from a tree outside his home, Detective Lottie Parker is called in to lead the investigation. Both bodies have the same distinctive tattoo clumsily inscribed on their legs. It's clear the pair are connected, but how? The trail leads Lottie to St Angela's, a former children's home, with a dark connection to her own family history. Suddenly the case just got personal.

When a 15-year-old girl fails to make it home after school, DI Heather Filson believes she’s dealing with just another teenage runaway. The girl’s grandfather, a notorious Glasgow gangster, disagrees. Convinced one of his underworld enemies has grabbed her, he’s prepared to bathe the city in blood in order to bring his princess home.

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.

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.