(Hor '64,BW). Auturo Fernandez, Soledad Miranda, Antonio Casas, James Philbrook, Ingrid Pitt, Jose Badalo. An excavation team working in Greece is menaced by a prehistoric monster that's not only noisy but invisible.

Professor Andre, his daughter Maria, and his assistant Stavres, are searching for buried treasure with the aid of half a map in a Greek cave that is considered taboo by the local peasants. Using an explosive, they unearth two pods, actually the eggs of brontosaurus-like creatures that become invisible and make horrifying noises when in motion. The group takes one of the two eggs home for examination; the other cracks open and rolls away. Months later, driver-guide Pete and an Italian woman named Sofia join the expedition, bringing with them the missing half of the map. When the treasure's exact location is found and more dynamite is needed, Stavres is left behind in the cave and is slashed to death by the now-hatched creature. After the professor is also killed, Pete devises a plan to maim the monster but succeeds only in wounding it. An assistant then sacrifices his life by setting himself and the creature on fire, thereby saving the others.