Cash's girlfriend Lenora receives a mysterious letter from a working girl in Yankton, pleading for help. Limping Lilly Loftus is not one to cry wolf, so Cash agrees to take Lenora. Before long, their investigations lead them to The Dark Swan, a steamboat on the Missouri. The vessel is hosting not only European royalty but a prestigious high-stakes poker contest. Attractive Princess Augusta Letitia Fitzosbern has entered the poker...