Scientist working on synthetic nutrients using atomic energy accidentally unleashes a giant spider in the American Southwest. His formula also has some unfortunate side effects on humans. . .

Probably the best of the big bug movies of the Fifties, along with Them!, thanks to a clever script and solid, believable performances. Leo G. Carroll is driven, but hardly the stereotypical 'mad' scientist (indeed, his predictions of future famine have proven sadly true), and the romance between Corday and Agar is pleasantly low-key. Plus, Dirty Harry napalms the big spider in the climax. How cool is that?