Sent to live with their nearest living relative, Sir Septimus Wellynghame Cloy, the eccentric and rather sinister widower of their late mother's half-cousin, Mog and Nick find themselves spending a lot of time on their own, exploring. Two elderly manservants, Melibee and Bonefinger, guard Cloy and his house like malevolent ravens and, when strange things begin to happen - a falling gargoyle just missing them in the churchyard, a flagstone collapsing beneath their feet - the twins start having the same dream. Is Damyata at large again? References in old documents lead them to unveil some dark secrets in the history of the house, in particular 'the story behind the hangings' so, when their governess is found hanged, they fear 'the hangings' may have started again. Can the twins discover the truth behind the house and its family secrets, before their own lives become endangered?