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.

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.

It was meant to be a harmless stag-night prank. But a few hours later, the groom has disappeared and his friends are dead. With only three days to the wedding, Roy Grace is contacted by the man’s distraught fiancée to unearth what happened on that fateful night. The one man who ought to know of the groom’s whereabouts is saying nothing. But then he has a lot more to gain than anyone realizes, for one man’s disaster is another man’s fortune.

Responding to reports of deadly screams in the Ironbridge Gorge, Detective Sergeant Jenna Morgan is first on the scene to investigate. As the search intensifies, Jenna soon discovers her sister Fliss’ severely injured Dalmatian, Domino, and the naked, tortured body of an unknown woman.

A family is gunned down in the snow, but one of the children survives. Three years on, that child takes revenge, and the Snow Killer is born. But then, nothing - no further crimes are committed, and the case goes cold. 50 years later, has the urge to kill been reawakened? As murder follows murder, the detective team tasked with solving the crimes struggle with the lack of leads. It’s a race against time and the weather - each time it snows, another person dies.