When the Japanese freighter Eiko-maru is destroyed near Odo Island, the Bingo-maru is sent to investigate, only to meet the same fate with few survivors. A fishing boat from Odo is also destroyed, with one survivor. Fishing catches mysteriously drop to zero, blamed by an elder on the ancient sea creature known as "Godzilla". Reporters arrive on Odo Island to further investigate. A villager tells one of the reporters that "something large is going crazy down there" ruining the fishing. That evening, a ritual dance to appease Godzilla is held during which the reporter learns that the locals used to sacrifice young girls. That night, a large storm strikes the island, destroying the reporters' helicopter, and an unseen force destroys 17 homes, kills nine persons and 20 of the villagers' livestock.
Far north of the Arctic Circle, a nuclear bomb test, dubbed "Operation Experiment", is conducted. Prophetically, right after the blast, physicist Thomas Nesbitt (Paul Christian) muses, "What the cumulative effects of all these atomic explosions and tests will be, only time will tell." No sooner said, the explosion awakens a 30-foot (10 m) tall, 100-foot (30 m) long carnivorous animal known as Rhedosaurus, thawing it out of the ice where it had been held in suspended animation. Nesbitt is the only witness to the beast's awakening and is later dismissed out-of-hand as being delirious at the time of his "sighting". Despite the skepticism he persists, knowing what he saw.
A scientist develops a formula which will cause animals to regress to the form of their primitive ancestors, and tries it on himself with disastrous results.
Evil Moon robot Ro-Man Extension XJ-2 (George Barrows), referred to as just Ro-Man, has seemingly destroyed all human life on Earth with a Calcinator death ray, all except for eight humans that remain alive. The survivors are an older scientist (John Mylong), his wife, two daughters, his young son Johnny (Gregory Moffett), his assistant, and two space pilots that shortly take off in a spaceship for an orbiting space platform. All eight have now developed an immunity to Ro Man's death ray, having received an experimental antibiotic serum developed by the scientist.
The film series is a complicated serial with more twists than a maze that basically centers around a U.S. Air Force captain and his quest for missing microfilm that contains vital information. The heroic Buster Crabbe plays Captain Roger Drum, who shoots down an enemy plane on its way to Africa with the secret microfilm. Intent on revealing the subversive group that the message was for, Drum assumes the pilot's identity and flies to Africa himself and crashes in the jungle. He is rescued by the pacific Rock People, led by Princess Pha (Gloria Dea), and is renamed Thunda, King of the Congo, after he rings a temple gong in alarm. With the subversives believing Thunda is their missing pilot and under constant attack by another tribe called the Cave Men, our hero plots to bring down the subversives who are searching for a new metal more radioactive than uranium. At the end, Thunda (or Drum) clears the jungle of villains and reunites the Rock People and Cave Men for well.
Maj. Joe Nolan (Cesar Romero) is the head of an expedition to the South Pacific to retrieve an atomic-powered rocket that vanished without a trace. He had previously lived in a South American jungle, as has fellow serviceman and pilot Lt. Danny Wilson (Chick Chandler), who is also on the expedition. Aircraft mechanic Sgt. William Tatlow (Sid Melton) is also recruited for the expedition, which includes the three scientists who helped build the rocket.
The year is 1830. The American clipper ship, the Queen, is attacked by pirates in the New Hebrides (present day Vanuatu). The ship's mate Kirk Hamilton (Arness) is wounded and heads to Queensland, Australia for medical treatment. While at the hospital, he meets and falls in love with Elaine Jeffries (Rogers), the fiancee of Martin Shannon (Bill Kennedy) a rancher. A romantic rivalry develops and the pirates, who attacked Kirk and his ship kidnap her along with her friend, Nancy Holden (Jane Harlan). Kirk and Shannon pursue the pirates and they soon wind up on a volcanic island, inhabited by dinosaurs.
Tigri (Luez) and her stone age friends, all of which are women, hate all men. However, she and her Amazon tribe see men as a "necessary evil" and capture them for potential husbands. Engor (Nixon), who is smarter than the rest of the men, is able to escape them. He discovers fire and battles enormous beasts. After he is recaptured by the women, he discovers fire and drives off a dragon-like creature. The women are impressed with him, including their prehistoric queen. Engor marries Tigri and they begin a new, more civilized, tribe.
The Stooges are cavemen living in the stone age. They must tend to their daily chores, consisting of mixing milk, hunting fish, and gathering eggs. Such is life in the prehistoric times.
Adventure-seeker Ted Osborne (Phillip Reed) and his fiancee Carole (Virginia Grey) are at a cafe in Singapore, looking for a charter to an island supposedly inhabited by dinosaurs. They come across the ruthless, two fisted, alcohol-suffering Captain Tarnowski (Barton MacLane). They decide to talk, and Osborne asks is Tarnowski is willing to give them a charter in his ship to the unknown island. Initially Tarnowski refuses, but then Osborne tells that during World War II he was a pilot in the US Navy. He had flown over many remote islands, and on one he reported seeing large, moving things that looked like Brontosaurus dinosaurs. He shows Tarnowski a photo, and the captain finally agrees to take them there. Before departing, Tarnowski introduces them to John Fairbanks (Richard Denning), an old friend of his, who agrees to help them with their quest. Fairbanks and a group of friends had been shipwrecked on the island with Fairbanks being the lone survivor of attack by the dinosaurs. As Fairbanks had been drinking incessantly to forget the events of the past since his rescue, his account of the dinosaur island was believed to be the result of alcoholism and insanity. Since Fairbanks and Osborne's stories collaborated, Tarnowski agrees to allow his ship to be hired, but specifies that no one in the crew be told of their destination.
Le film est composé de sept séquences illustrant huit morceaux de musique classique, réorchestrés et dirigés par le chef d'orchestre Leopold Stokowski à la tête de l'Orchestre de Philadelphie. La dernière séquence illustre deux morceaux et un intermède sépare la séquence 4 et 5. Chaque séquence est précédée d'une courte introduction où l'orchestre est en ombre chinoise.
In a modern day prologue, a group of hikers caught in a storm seek shelter in a cave. They encounter an anthropologist (Conrad Nagel, "The Narrator") who interprets prehistoric carvings that introduce the story of a young caveman.
In New York Harbor, Carl Denham, famous for making wildlife films in remote and exotic locations, charters Captain Englehorn's ship Venture for his new project, but he is unable to secure an actress for a female role he reluctantly added. Denham searches the streets of New York for a suitable woman. He meets penniless Ann Darrow and convinces her to join him for the adventure of a lifetime. The Venture quickly gets underway. The surly first mate, Jack Driscoll, gradually falls in love with Ann. After weeks of secrecy, Denham finally tells Englehorn and Driscoll that their destination is Skull Island, an uncharted island shown on a map in Denham's possession. Denham speaks of something monstrous there, a legendary entity known only as "Kong".
The story picks up about a month after the dramatic finale of the previous film and follows the further adventures of filmmaker Carl Denham, now implicated in numerous lawsuits following the destruction wrought by Kong. Denham leaves New York with the captain of the Venture, Captain Englehorn, who is certain it is just a matter of time before he is similarly served. Their efforts to make money shipping cargo around the Orient are less than successful. In the Dutch port of Dakang, Denham is amused to see there's a "show" being presented, so he and Englehorn attend. It turns out to be a series of performing monkeys, capped by a song ("Runaway Blues") sung by a young woman named Hilda.