Two innocent women have been brutally murdered, their bodies left at neolithic burial sites across the island of Jersey. Detective Inspector Winter Labey leads the investigation, calling on forensic psychologist Saskia Monet to help unravel the killer’s twisted motives.

But Saskia harbours a dark secret of her own that threatens to derail the case, and when a suspect emerges with a connection to the prison where Saskia works, the investigation begins to hit dangerously close to home. Even as she hides parts of her past from Winter, Saskia’s feelings for him are growing – but can he ever trust her when she’s told so many lies?

It’s a race against time as they try to piece together the clues left in the ancient burial chambers. Can they overcome their differences in time to bring the killer to justice? Or will the dark secrets from Saskia’s past catch up with them both, and more innocent lives will be lost to the Island of Graves?