After discovering the secrets of a 140,000-year-old spacecraft and delivering it to safety in the smash hit Saucer, Rip and Charley think their days of high-flying extra-terrestrial adventure are over. But bored with Rip's aimless wanderings, Charley accepts a job flying space planes to the moon for the French lunar base project, where she discovers a world-threatening anti-gravity beam that could only have been constructed using saucer technology.

She steals a space plane and flies back to earth to sound the warning. Meanwhile, the French kidnap Rip's uncle Egg and force him to fly a saucer hidden in Area 51 to the moon. Rip and Charley must steal the first saucer from its new home at the museum and hit the not-so-friendly skies again in order to rescue Uncle Egg and save the world from a twisted modern-day Napoleon bent on conquest.