The residents of a small town are excited when a flaming meteor lands in the hills, until they discover it is the first of many transport devices from Mars bringing an army of invaders invincible to any man-made weapon, even the atomic bomb.
Test space rockets exploding at liftoff and increased reporting of UFO sightings culminate in a direct attempt by alien survivors of a dead, extra-galactic civilization to invade Earth from impervious flying saucers, using ray-weapons of mass destruction.
At the end of the 22nd century Alisa Seleznyova, her father Professor Seleznyov and pilot Zelyony go on a space expedition to find rare animals for Moscow Zoo. On the way they seem to encounter a mysterious conspiracy led by Doctor Verhovtsev against legendary Two Captains Kim and Buran. The only clue is a talking bird Сhatterer [Govorun] that our heroes accidentally took possession of.
A group of scientists travel to a remote island to study the effects of nuclear weapons tests, only to get stranded when their airplane mysteriously explodes. The team soon discovers that the tests have given rise to crabs mutated into intelligent, impervious, telepathic giants intent on increasing their numbers by breeding, then travelling to populated areas to feed, and which do not intend to be stopped by their discoverers.
Scientists investigate a huge meteor that crashes into the ocean off Mexico, and encounter a skyscraper-tall, mobile machine which is designed to syphon energy from earth, including any energy directed at it in an effort to destroy it.
The Office of Scientific Investigations tracks down the source of increased magnetism and radioactivity in Los Angeles, and discovers that a man-made isotope is consuming available energy from nearby mass every few hours, doubling its size in the process. Although microscopic, it will soon become big enough to destroy Earth; and how to stop it is yet to be determined. The film's Deltatron special effects footage is taken from the 1934 German sci-fi film GOLD.
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.
An attractive reporter investigating the mysterious destruction of an Illinois town stumbles upon a secret government laboratory conducting radiation experiments on vegetables. The lead scientist is eager to help find out what happened. Together they discover that giant grasshoppers are behind the devastation. Worse yet, thousands of them are headed toward Chicago! Can they be stopped... or is this the BEGINNING OF THE END?
The first American space station Skylab is found in pieces scattered in Western Australia. Putting these pieces back together and re-tracing the Skylab program back to its very conception reveals the cornerstone of human space exploration.
Commando Cody, 'Sky Marshal of the Universe', works with American scientists Joan Gilbert and Ted Richards in the development of a flying suit and a rocket to the Moon. When the nation's defences are being sabotaged and destroyed, Cody learns that an atomic-gun is being used and that the men on the moon are the culprits.