Lieutenant David Miller has all the right credentials: Annapolis graduate, the gold wings of a naval aviator, and the recent completion of the Navy's counterintelligence school. But he is lacking the most important ingredient in the real and deadly world of espionage-experience. His clandestine assignments use the luxurious Boeing 314 flying boat, operated by Pan American, as a cover and on this trip he is to assure the safe passage of a Chinese Envoy, who is to deliver a secret document from President Roosevelt to Premier Chiang Kai-shek. The new four-engine 'Pacific Clipper' arrives in San Francisco in June 1941, to start the first leg of its 8,000-mile journey to the orient and Miller begins an unintended relationship with one of the passengers, a Japanese-American. His prejudice is tempered by her decidedly 'American' culture and personality but he is unsure of her loyalty to America. While aware of his shortcomings in espionage, Miller is totally unsuspecting of how ill prepared he is for a first serious encounter with a young lady who is aggressive for his affections. Will this relationship compromise the mission?