A Royal Abduction

During a state visit to Australia in 1928, Her Royal Highness Princess Natalie, heiress to the throne of Rolandia in Europe, is abducted from the transcontinental train at Cook on the Nullarbor Plain by a gang lead by American gangsters, Earle Lawrence and Van Horton. They hide her in caves near Eucla on the Great Australian Bight until the search is called off and ransom is arranged.