The scene opens in the house of a tidy old spinster, living in a tidy little seaside town, in a row of large houses of similar people, sharing private access to a well-kept garden. A rather stable existence. There is also a nice young American girl, over in England as part of her education, no doubt. Her father has become very rich in America, but he is the brother of the tidy old spinster, on whom, and to whose dismay, he has imposed Cornelia's visit. Cornelia is simply not used to the standards of English behaviour, for instance chaperones, and not gadding about with young men. Cornelia has quite enough pocket-money to do as she pleases. But her aunt is proved right in the end, for among all these nice well-brought-up people there is a baddy, which is revealed only towards the end.