Navy Commander Alan Roberts is assigned to lead an expedition to Little America in Antarctica to investigate reports of a mysterious warm water inland lake discovered a decade earlier. His helicopter and its small party, including reporter Maggie Hathaway, is forced down into a volcanic crater by a fierce storm. They find themselves trapped in a lush tropical environment that has survived from prehistoric times.
An evil alien brain, bent on world domination, takes over the body of an atomic scientist, while a "good" alien brain inhabits the body of the scientist's dog and waits for an opportunity to defeat the evil brain.
A test pilot is missing and a search party is sent out in the jungles of Mexico; however, while searching they uncover a monster in the jungle who became this way due to a dose of radioactivity.
A small town doctor mistakenly ingests an experimental drug made from the blood of vampire bats which transforms the kindly medic into a bloodthirsty monster.
With his assistant, Laura Hutchinson, Dr. David Conway develops a device to advance the fledgling science of earthquake prediction. After forecasting a large trembleor that will rock California within twenty-four hours, Conway cannot persuade the Governor to act. When the prediction proves true and further tests indicate that there are more quakes to come, Conway and Laura seek to perfect their device. Subsequent tests deep within Carlsbad Caverns discover an unknown element—E-112—that is responsible for the earthquakes and threatens to destroy the globe if it ever reaches the surface. The team determines that with only four weeks until Armageddon, the race is on to neutralize the killer element before it takes a devastating toll.
Baron Victor Frankenstein has discovered life's secret and unleashed a blood-curdling chain of events resulting from his creation: a cursed creature with a horrid face — and a tendency to kill.
A test rocket carrying wasps to outer space, to study the effects on them of weightlessness and radiations, crashes out of control back to Earth, into the jungles of Africa. The two astrobiologists in charge of the test mount an expedition to the Darkest Continent to retrieve their experiment, only to find the wasps have grown to giant size which are panicking all forms of life as they quest for food.
A wealthy business man discovers he has a brain tumor and seeks medical help. The business man finds a scientist experimenting with transplanting monkey heads on different monkey bodies. The business man decides to steal the head of Nostradamus from the prophet's crypt.
A giant prehistoric praying mantis, recently freed from the Arctic ice, voraciously preys on American military at the DEW Line and works its way south.
Deep in the jungles a mad scientist is using the natives' voodoo for his experiments to create an indestructible being to serve his will. When a party of gold seekers stumbles upon his village, the scientist realizes that Marilyn the expedition's evil leader is the perfect subject for his work.
A dangerous combination of radiation and insecticide causes the unfortunate Scott Carey to shrink, slowly but surely, until he is only a few inches tall. His home becomes a wilderness where he must survive everything from spiders living in the cellar to his beloved cat.