One day, an alien (Ulli Birve) from the distant planet Epsilon materializes in the Australian outback. She's helped by a local surveyor (Syd Brisbane), who doesn't understand the alien's revulsion at being trapped on Earth. She explains that throughout the galaxy, humans are regarded as destructive creatures who are too ignorant to save themselves from certain destruction. She takes the surveyor on a time-traveling journey around the world to show him the effects of mankind's thoughtlessness.

After Roxy Miller (Marilyn Manning) encounters enormous caveman Eegah (Richard Kiel) while driving down a remote California road, her writer father, Robert (William Watters), heads out to the desert to prove his daughter's claims are true. Once there, Robert is knocked unconscious and trapped in Eegah's cave, where he gains some insight into prehistoric life. But, when Roxy and her boyfriend, Tom (Arch Hall Jr.), come to rescue Robert, Eegah grows fond of the girl and refuses to let her leave.

Rich oddball Frederick Loren (Vincent Price) has a proposal for five guests at a possibly haunted mansion: Show up, survive a night filled with scares and receive $10,000 each. The guest of honor is Loren's estranged wife, Annabelle (Carol Ohmart), who, with her secret lover, Dr. Trent (Alan Marshal), has concocted her own scheme to scare Loren's associate, Nora Manning (Carolyn Craig), into shooting the potentially crazy millionaire. But more spooks and shocks throw a wrench into the plan.