A carnival showman tries to keep Japanese spies from sabotaging the Panama Canal.

During the start of the Pacific campaign in World War II, Lieutenant Janet Davidson is the head of a group of U.S. military nurses who are trapped behind enemy lines in the Philippines. Davidson tries to keep up the spirits of her staff, which includes Lieutenants Joan O'Doul and Olivia D'Arcy. They all seek to maintain a sense of normal life, including dating, while under constant danger as they tend to wounded soldiers.