England, 1924. Lady Adelaide Compton has recently (and satisfactorily) interred her husband, Major Rupert Charles Cressleigh Compton, hero of the Somme, in the family vault in the village churchyard.

Rupert died by smashing his Hispano-Suiza on a Cotswold country road while carrying a French mademoiselle in the passenger seat. With the house now Addie's, needed improvements in hand, and a weekend house party underway, how inconvenient of Rupert to turn up—not in the flesh, but as a spirit! Rupert has to perform a few good deeds before becoming welcomed to heaven—or, more likely, Addie thinks, to hell.

Before Addie can convince herself she hasn’t completely lost her mind, a murder disrupts her careful seating arrangement. Which of her twelve houseguests is a killer? Her mother, the formidable Dowager Marchioness of Broughton? Her sister, Cecilia, the born-again vegetarian? Her childhood friend and potential lover, Lord Lucas Waring? One of the others? Rupert has a solid alibi as a ghost and now an urge to investigate.

Enter Inspector Devenand Hunter from the Yard, an Anglo-Indian who is not going to let some barmy society beauty, witnessed talking to herself, derail his investigation. Something very peculiar is afoot at Compton Court, and he's going to get to the bottom of it—or go as mad as its mistress trying.