The hero of this story is Walter Leigh, who takes a job as second mate aboard a gasoline-powered yacht owned by a Mrs. Vansittart, whose husband is an American industrialist. Julius Vansittart is a rather nasty 12-year-old, who, despite his life being saved by Leigh, when he had fallen overboard, hates the English, and never misses an opportunity of being as unpleasant as possible, even to the point of stupidity.