Old Sam Button spent his life chasing one impossible dream: to be the first man on the Moon. Brilliant, relentless, and utterly devoted to science, he pushes the nation toward a future no one else can quite imagine. He wins over Congress, inspires the public, and helps launch a billion-dollar leap into history. At last, the moment arrives. The world watches breathlessly as Sam's ship settles onto the lunar surface. The cameras are rolling. The speeches are ready. The flag is in hand. And then the door won't open. What follows is one of science fiction's sharpest and funniest ironies: a triumphant human achievement undone by a tiny, absurd mistake. In Michael Shaara's witty, satirical tale, ambition collides with bureaucracy, pride, and the fragile machinery of progress. With dry humor and keen insight, Shaara turns the space race into a comic masterpiece about grand dreams, human error, and the strange way history remembers its heroes. Both hilarious and quietly poignant, Four-Billion Dollar Door is a sparkling classic of speculative fiction that asks what happens when the future arrives—and someone forgets to unlock the door. This edition has been fully restored with modern typesetting, custom cover design.