Sent to live with their nearest living relative, Sir Septimus Cloy, the eccentric widower of their late mother's cousin, Mog and Nick spend a lot of time on their own. They explore the Cloy mansion, with its towers and turrets, staircases leading nowhere, and forbidden rooms. Two elderly manservants, Melibee and Bonefinger, guard Cloy like malevolent ravens. Then sinister things begin to happen: a falling gargoyle misses them in the churchyard, a flagstone collapses beneath their feet, and their governess is found hanged in her room. References in old documents point to some dark secrets in the history of the house, and the village is rife with rumors. Is the mysterious Damyata, a villian from Mog's past, at large once again? And can the twins discover the truth behind the family mansion and its secrets, before their own lives become endangered?