Henry Pulling, a retired bank manager, meets his Aunt Augusta. Soon she persuades him to abandon his dahlias and neighbours to travel with her through Europe's hotel society, meeting a wide variety of unusual characters.

This is the story of Kitty Fane, the adulterous wife of a bacteriologist stationed in Hong Kong. When her husband discovers her deception, he exacts a terrible vengeance: Kitty must accompany him to the heart of a cholera epidemic in China.