Edie Burchill and her mother have never been close but, when a long-lost letter arrives with the return address of Milderhurst Castle, Kent, Edie begins to suspect that her mother's emotional distance masks an old secret. Evacuated from London as a thirteen-year-old girl, Edie's mother was chosen by the mysterious Juniper Blythe and taken to live at Milderhurst Castle with the Blythe family.

Fifty years later, Edie, too, is drawn to Milderhurst and the eccentric Sisters Blythe. Old ladies now, the three still live together as the twins nurse Juniper, whose abandonment by her fiance in 1941 plunged her into madness. Inside the decaying castle, Edie begins to unravel her mother's past.

But there are other secrets hidden in the stones of Milderhurst Castle, and Edie is about to learn more than she expected. The truth of what happened in the distant hours has been waiting a long time to be uncovered