1951, Brixham, Devon.

Inspector Alun Ryga heads to the coast with photographer Eva Paisley. They are staying with Eva’s old friend Anna and her nine-year-old son Jean-Claude.

Jean-Claude is convinced he saw a body on the shore ‘all bashed up’ and claims a mermaid took it away. It’s all he’s been talking about for a week!

Intrigued, Ryga asks Jean-Claude to take them to the harbour. And sure enough a man’s body is there, wrapped in nets, with a stab wound to the heart.

Jean-Claude was right. But who’s the victim? And what prompted the little boy to come up with the idea of a mermaid?

Ryga begins to investigate, but the discovery of another body throws him into turmoil.

Someone is killing to keep their secrets hidden. And with Ryga hot on their heels, he could be next.