When DI Ben Kitto sees a baby thrown into Penzance harbour he prays it’s a trick of the light. But the threat is real. The child survives - barely - and soon a chilling pattern emerges. As the Burning Sky Festival brings dancers dreamers and stargazers to Cornwall’s coast children begin to vanish. A small mermaid figurine is found beside each scene echoing the legend of the Mermaid of Zennor who lured a man to his death beneath the waves. Still reeling from a devastating bereavement and determined to protect his young son Ben is pulled into a deadly investigation. Then the killer’s messages begin arriving at his home. As the summer solstice approaches Ben must confront the boundaries of love loss and obsession. In a final desperate chase along the headland only his bond with Noah - and the loyalty of his dog Shadow - can prevent tragedy from repeating itself.