A textbook example of '50s-era science fiction, Earth vs. the Flying Saucers boasts not only a solid script and competent performances, but some genuinely impressive stop-motion effects courtesy of one of the industry's uncontested masters, Ray Harryhausen. Scientist Hugh Marlowe (who faced a more benevolent invader from space five years earlier in The Day the Earth Stood Still) discovers that UFOs are responsible for the destruction of a series of exploratory space rockets launched by his space exploration project. The saucers' helmeted pilots land on Earth and deliver an ultimatum to humanity via Marlowe: fealty or complete annihilation.