William MacDonald, Earl Pastko and Paralee Cook star in this sci-fi thriller in which the survival of mankind depends on a madman convincing others to believe his bizarre theory that extraterrestrial parasites are scheming to wipe out all mankind. Trying desperately to get someone to take action, Martin begs a young couple to take him seriously, and they must decide whether they're dealing with a lunatic or whether Martin's crazed rants are true.