The semi-invalid Mrs. Moulton and her long-suffering husband are touring Europe with their two adult daughters, Jane and Lydia. They have firm ideas of what is proper and decorous. Mr. Moulton's young relative, Catalina, does not fit this ideal. Her dress is too short. She mixes with the natives. She wants to visit Spain... not, in itself, a problem; except she proposes to travel in a third class compartment on the train! Funds will not stretch to any other class, and if the Moultons refuse to accompany her, she proposes to walk! What will become of them all? Surely only doom, disaster and the loss of reputation lie ahead.