Susan begins a search operation in a remote area of Mexico to locate her fiance Bruce. The team finds a gigantic one-eyed monster who became disfigured due to exposure to excess radioactivity.
In the 21st century, aliens invade the solar system. Using Mars as their base, they steal all of Earth's space stations then brainwash or kill the crews.
A rescue team is sent to Mars to bring back an astronaut who claims that a Martian monster killed his team. As they return to Earth, they sense the presence of the creature in the spaceship.
The true value of an estate brings out the worst in the deceased's doctor (Christopher Lee), lawyer, sister (Joan Collins) and rightful heir (Robert Hardy).