Nellie Burns and Moonshine to the rescue! A wounded sheriff, Nellie, and her dog Moonshine, accompanied by Nurse Janie and gangster moll Frankie, ride a scow on the Salmon River—the River of No Return—to capture a murderer and bring him to justice. Their adventures in 1920's Idaho land them in the water, at a gold mine site, and finally, a river town and a snowstorm.