Maisie is hitch hiking back from Texas, as the show that she was playing in finished two days ago. It's hot and dusty, the ranches are huge, and it's taking her forever! About to give up, a car pulls up alongside, and a woman offers her a lift. The woman's name is Harriet, and she and her husband own a dude ranch in the Rio Grande. They're trying to get the place running, but the guests there right now are hankering after some pretty young cowgirls. Thinking she can spice things up a little, 'Mysterious Maisie' offers her services to Harriet and Frank, under the guise of being a secret agent...