This story is set in the last years of the Regency, and is narrated by Ennis Corbyn, a spirited young woman, but no beauty, who is adopted by the rich and lonely Marquesa de Verletta, and by her introduced into the highest flight of society. The Marquesa's wealth and rank, and the flattering attention of the Prince Regent, are responsible for Ennis's social success. In spite of which her life with the Marquesa at The Abbot's House is overshadowed by fear, and the sinister secret hidden behind the locked door of the old wing, which nobody, unless accomplished by the Marquesa, is allowed to enter. Ennis loves the dashing Damien Wynton of the Hell Fire Club, and is resolved she will marry him and no other. But Damien avows that love for him is only sweet for a day, and there is Oliver Embury, one of the Prince Regent's aides, who swears he will be true to her always. This is the background for a sparkling tale of love, adventure and eerie happenings.