When John Vigilia, a writer and stunt pilot, travels to Europe to explore the truth behind a story he's been told about a young boy who flew as Lindbergh's secret copilot on his trans-Atlantic flight, he finds himself in the middle of international intrigue. While investigating the story, John realizes he is being followed, and someone has even tried to kill him. Has he discovered the conspiracy of the century, or is it just an old man's hoax? After tracing Ariel Angelucci through Ireland, Rome, Como, and Munich, Vigilia finally finds him in Switzerland. Angelucci reveals that he did indeed fly with Lindbergh. Not sure if he believes the story, John takes the man for a flight in a biplane to discover if he really knows how to fly. The old man wants to perform some "stunts," but suffers a heart attack at the top of a loop, jamming the controls and causing the aircraft to crash.
When John Vigilia regains consciousness in a private clinic on an island in Lago Maggiore, he realizes he is being kept prisoner because of what he knows.