Detective Sam Helsdown hasn’t seen his daughter Zoe in two years and he’s excited and more than a little nervous to be at the airport picking her up for a visit. She’s 10 years old and has flown on her own for the first time. Flight BA631 from Athens has already landed and soon a trickle of people begins entering Arrivals. Among them is a little girl who runs towards him, head down, and throws herself into his arms saying ‘Daddy!’. But then he looks at her properly. This is not Zoe. This is not his daughter.

London, 1921. The Great War has recently ended and tensions in England are high. Now, prominent Cabinet minister Lord Amersham has been shot dead outside his Regent's Park home. The signs point to a professional hit. Charged with solving one of the most sensitive and high-profile cases Scotland Yard has ever faced, DCI Paul Stark is under pressure to get the job done quickly.

DI Ivan Winterman is a man with a troubled past. The Blitz has left his young son dead and his wife seriously injured. He has made enemies in high places, and, with his career going nowhere, he returns to his home town in East Anglia, seeking to rebuild his life. As the snow begins to fall, a drunken ex-clergyman stumbles on the semi-mummified body of a small child concealed in a ruined cottage. Days later, a second child's body is found in a Fenland dyke. Winterman, supported by a small team of assorted misfits, finds himself uncovering a web of secrets in the small rural community.

On a hot July morning on Sweden's idyllic vacation island of Sandhamn, a man takes his dog for a walk and makes a gruesome discovery: a body, tangled in fishing net, has washed ashore. Police detective Thomas Andreasson is the first to arrive on the scene. Before long, he has identified the deceased as Krister Berggren, a bachelor from the mainland who has been missing for months. All signs point to an accident - until another brutalized corpse is found at the local bed-and-breakfast.

When DI Joe Burton and DS Sally Fielding are called to investigate a suspicious death in a care home, it is just the start of their problems. As further bodies are discovered, with playing cards placed beside their bodies, the Manchester police realise they have their work cut out. With the press closing in on the case, a criminal profiler is called in to help work out what the killer’s motive is. With the clock ticking and more victims uncovered, Fielding and Burton must race to track down a twisted killer before it’s too late.