1805. An engagement party is taking place for Mr. Richard Montague, son of wealthy landowner Sir Edgar Montague, and his fiancée Catherine. During a dance with his beloved, a strange thing happens: a man appears at Richard's shoulder and appears to communicate something to him without saying a word. Instantly breaking off the engagement, Richard rushes off to speak to his father, never to be seen again. Distraught with worry, Catherine sends for her spinster aunt, Miss Dido Kent, who has a penchant for solving mysteries. Catherine pleads with her to find her fiancé and to discover the truth behind his disappearance. It's going to take a lot of logical thinking to untangle the complex threads of this multi-layered mystery, and Miss Dido Kent is just the woman to do it.

Madderstone Abbey, 1806.When Penelope Lambe suffers a bad fall in Madderstone Abbey, some are sure she must have seen the Grey Nun, the ghost reputed to walk the ruins. Miss Dido Kent is not convinced, and is determined to uncover the real cause of the accident.Then events take a sinister turn when a human skeleton is found nearby. The remains are identified as those of a Miss Elinor Fenn, and letters come to light which hint at the reason for her death. But is Miss Lambe's accident connected to this discovery? Did she see a ghostly warning? Or is there a rational explanation? Everyone is relying on Dido to find out.

Madderstone Abbey, 1806. When Penelope Lambe suffers a bad fall in Madderstone Abbey, some are sure she must have seen the Grey Nun, the ghost reputed to walk the ruins. Miss Dido Kent is not convinced, and is determined to uncover the real cause of the accident. Then events take a sinister turn when a human skeleton is found nearby. The remains are identified as those of a Miss Elinor Fenn, and letters come to light which hint at the reason for her death. But is Miss Lambe's accident connected to this discovery? Did she see a ghostly warning? Or is there a rational explanation? Everyone is relying on Dido to find out.

It's Richmond, 1806. Miss Dido Kent has developed rather a taste for mysteries, having solved the riddle at Belsfield Hall. When her quiet holiday with her cousin Flora is disturbed by the suspicious death of a neighbour, Miss Dido is once more at the centre of an unusual investigation. All eyes have fallen on the late Mrs Lansdale's nephew 'for it has not passed without notice that he has lost a remarkably tyrannical relation and gained a very fine inheritance'. Miss Dido is intrigued by the rumours and, at Flora's behest, starts a little investigation of her own. And as she does so, she brings more to light than even she could have imagined.