Constance Strong (Adele Mara) arrives at Rock Island for the competition between a railroad line, a steamboat and a stagecoach for a profitable mail contract. Constance befriends Reed Loomis (Forrest Tucker), the head of the rail line, but is engaged to Kirby Morrow (Bruce Cabot), the owner of the steamboat. After the rail line easily wins the competition, the rivalry between Loomis and Morrow continues, and Morrow grows to resent his loss of the contract and, apparently, Constance.