A civilian volunteer trains to fly aboard the Lockheed U2, the Cold War spy plane still used for reconnaissance from the edge of the atmosphere. The film follows him through US Air Force preparation, including a high-altitude vacuum chamber where water boils at room temperature and drills on emergency ejection procedures. He is fitted for a pressure suit worth a quarter of a million dollars, built to the same standard as the suits Apollo astronauts wore, and learns why it is the only thing keeping him alive above 70,000 feet. Once airborne, the U2 operates inside what pilots call the coffin corner, the narrow margin between stalling and overspeeding at altitudes far above commercial air traffic. Cockpit footage shows the curvature of the Earth and the dark sky above it, with the host narrating his own physical strain as cabin pressure and thin air push against the suit. It is a hands-on look at what flying one of the most demanding aircraft ever built actually requires.