When seismic tremors cause the birth of a new volcano in Mexico, a team of geologists heads to investigate. They soon discover to their shock that the quake has rent a path to the surface world for a swarm of giant─and hungry─prehistoric scorpions. Creepy-crawly creature feature offers monsters by stop-motion maestro Willis O'Brien ("King Kong"); Richard Denning, Mara Corday, Carlos Rivas star. 88 min. Widescreen; Soundtrack: English Dolby Digital mono.