Clara has been sent to stay with her aunt and uncle while England is at war. But when she reaches their cottage on an enormous country estate, Clara is plunged into a tangle of secrets… A dark, locked room, a scheming thief, and a mysterious boy who only appears at night.

Clara has a secret of her own too – a terrible one about her brother, fighting in the war. And as the secrets turn to danger, Clara must find the courage to save herself, and those around her…