| Director | Sam Newfield |
|---|
Major Joe Nolan is the head of a South Pacific expedition to retrieve an atomic-powered rocket that has vanished. He is accompanied by pilot Lieutenant Danny Wilson, aircraft mechanic Sergeant William Tatlow and the three scientists who built the rocket.
Their aircraft crashes on a remote, unknown tropical island in the area where the rocket had been lost on radar. The island's only residents are a native woman and her young brother. The woman indicates that something fell from the sky, and the rocket's fiery arrival caused the rest of the native population to abandon the island.
Expedition member Stanley Briggs is accidentally killed on the steep ascent up the escarpment. After long stretches of rock climbing, the expedition emerges from a toxic gas cloud cover. They discover a lush, prehistoric jungle inhabited by various dinosaurs and a large field of uranium, which is what disabled their electronic tracking equipment.
They encounter a Brontosaurus that attacks Robert Phillips as he retreats up a tree. Nolan and Wilson open fire, but the dinosaur's thick hide absorbs the bullets with little effect. Later that night, they establish camp. When Nolan awakes, he finds Phillips and Russian scientist Michael Rostov missing. Phillips is stuck in a large rock crevice near a Triceratops. Nolan accuses Rostov of intentionally arranging the accident, but Rostov insists that he was helping Phillips. The Triceratops nearly attacks the group, but another Triceratops appears and the two dinosaurs fight to the death.
Nolan is convinced that Rostov is evil because Rostov appeared to be able to save Briggs on their ascent but failed to do so. Rostov reveals that he is a victim of the Holocaust, in which he lost his wife and unborn child.
Wilson later shoots a Pterosaur for food near the rocket's landing site. The group discover that the rocket is surrounded by a Brontosaurus and a pair of Triceratops, but Nolan devises a strategy using their weapons that scare the dinosaurs. Rostov and Phillips retrieve the data from the rocket. With his back turned, Tatlow is gored to death by an angry Triceratops just as it is shot and killed by Nolan and Wilson. After the team finishes digging a grave, violent earthquake tremors begin and the team must hurry down the steep plateau.
The four men return to the island's flatland in time to escape the island by using an outrigger canoe. The survivors are finally able to watch from a safe distance as the island is rocked by more violent earthquakes, followed by a catastrophic eruption of the formerly dormant volcano, which ultimately destroys everything.