June 1933, and the Edevane family's country house, Loeanneth, is polished and gleaming, ready for the much-anticipated Midsummer Eve party. But by the time midnight strikes and the fireworks light up the night skies, the Edevane family will have suffered a loss so great that they leave Loeanneth forever. Seventy years later, after a particularly troubling case, Detective Sadie Sparrow retreats on an enforced holiday to her beloved grandfather's cottage in Cornwall. Venturing further into the countryside on her daily runs, she stumbles upon a long-abandoned house surrounded by overgrown gardens and dense woods, and learns the terrible story of a baby boy who disappeared without a trace. Meanwhile, the formidable Alice Edevane now leads a life as neatly plotted as the bestselling detective novels she writes. Until Sadie Sparrow starts asking questions about Alice's family's past, seeking to resurrect the complex tangle of secrets Alice has spent her life trying to escape . . . With a mystery that's become deeply personal to Sadie, and a novelist who is intent on hiding the past, can the secrets of that night ever be solved?