Captain Saxon, and agent for the top secret Omega agency, has been given the assignment of tracking down and either capturing or killing the crew members of a secret space mission who returned to Earth against orders. It seems that they were all infected with an alien parasite, and they were trying to bring its eggs back to Earth. The eggs were lost in an accident, and both Saxon and the astronauts are trying to locate them. What could the government want them for?

A devilish creature escapes from a carnival to wreak havoc on a small town.

While on a fishing trip, Harry Baldwin (Ray Milland) and his family hear an explosion and realize that Los Angeles has been leveled by a nuclear attack. Looters and killers are everywhere. Escaping to the hills with his family, he sets about the business of surviving in a world where, he knows, the old ideals of humanity will be first casualties. Not one to give up, he holds up a store for supplies and hides the family in a cave.

Rose is involved in a motorcycle accident, and has experimental surgery performed in order to save her life. However, she develops a taste for blood. Her victims grow in number as well as madness, turning the city into chaos.

A scientist living in an apartment complex kills a girl and uses acid to destroy her internal organs, and then kills himself. While investigating, a doctor discovers that the scientist was doing experiments on the use of genetically engineered parasites as organ transplants. Soon, other people in the complex begin showing signs of carrying the parasites, spreading the things through wanton orgiastic abandon, and the complex begins suffering an attrition problem.

A scientist from the failed Philadelphia Experiment leads a team of Navy SEALs back in time to the Cretaceous Period to rescue the first team he sent back during the 1940s. Things go wildly awry though, when on his return he accidentally brings a giant, man-eating dinosaur back through the portal and into modern-day, downtown Los Angeles.