In this science fiction adventure, John Fairbanks (Richard Denning) is a former Marine who, while on duty, discovered a previously unknown island in the Pacific where dinosaurs and other prehistoric animals have somehow managed to escape extinction and live as they did millions of years ago. Still traumatized by the experience, Fairbanks is persuaded to return by Ted Osborne (Philip Reed), a photographer who thinks that a few shots of some real live dinosaurs could shift his career into high gear. Accompanying John and Ted are the latters sweetheart Carol (Virginia Grey) and Capt. Tarnowski (Barton MacLane), the ships pilot -- who is not a man to be trusted. Ted and his crew soon find out that Johns story is true, and they discover why the danger has taken such a toll on him, as they soon find themselves on the run from hungry dinosaurs. ~ Mark Deming, All Movie Guide