Volcanic activity frees giant scorpions from the earth who wreak havoc in the rural countryside and eventually threaten Mexico City.

After a nuclear attack, an unlikely group of survivors, including a geologist, a crook and his moll, and a prospector, find temporary shelter in the remote-valley home of a survivalist and his beautiful daughter, but soon have to deal with the spread of radioactivity - and its effects on animal life, including humans.

Giant robots from Venus invade Chicago. Stranded in the deserted city are Frank and Nora (who has recently attempted suicide). They meet a celebrating couple at a café, Vicki Harris and Jim Wilson. The quartet escape the robot patrol and take refuge in a large hotel. There, they encounter a new danger in Davis, a psychopathic killer.