Irish Bowery lad Chimmie Fadden, is engaged to Hortense, whom he calls "The Duchess," the lovely French maid of his former employer, millionaire Van Cortlandt. When offered $10,000 to carry out an advertising campaign for Van Cortlandt's Western railroad, Chimmie agrees. As instructed, Chimmie travels to Death Valley, scatters gold nuggets around a deserted mine and reports a gold strike, which creates a sensation. When a government agent investigates, Chimmie arranges to be held-up, but Hortense and Miss Van Cortlandt, in San Francisco to see the Exposition, arrive and have the holdup men arrested. After bluffing the investigator, Chimmie, now famous, makes a record-breaking railway trip to New York to publicize the railroad. Exploiting the excitement, Van Cortlandt sells stock in the fake Chimmie Fadden Mining Company. When Chimmie's brother Larry tells Hortense of the swindle, she refuses to marry "a thief." Previously unaware of the company, Chimmie now returns the $10,000 to Van Cortlandt and tells the press about the scheme. Van Cortlandt returns the investments, and Hortense and Chimmie marry.