Maude Garrett is a World War II pilot on a secret mission. She boards a plane of an all-male crew, who immediately doubts her true intentions the moment they see her. As suspicion against her mounts, the crew decides to detain her inside the plane's gun turret until they figure out what her deal truly is. As this happens, two threats come into Maude's view: a Japanese fighter plane, and a mysterious shadow in the clouds.