Villain(s)  Prehistoric creature

Actor(s):  Chester Morris, Marla English, Tom Conway, Cathy Downs

Brief Description  It Conquered the World is a 1956 independent black-and-white science fiction film directed by Roger Corman, starring Peter Graves, Lee Van Cleef, and Beverly Garland. It follows a disillusioned scientist who helps a malevolent Venusian crustacean-like alien enslave humanity to eliminate human emotion, only to realize too late it brings total destruction.

Plot:
The story centers around Dr. Tom Anderson (Lee Van Cleef), a bitter, disillusioned scientist who believes that humanity is inherently flawed and doomed to destroy itself. Using a homemade, shortwave radio transmitter, Anderson establishes contact with an alien intelligence from the planet Venus. The Venusian tricks Anderson into believing that it wishes to guide Earth into a peaceful, utopian era by stripping humanity of destructive emotions and free will.

Anderson assists the alien by guiding an experimental Earth satellite into the Venusian's path, allowing the creature to hitch a ride and crash-land on Earth. The creature takes refuge in a nearby cave (filmed at the iconic Bronson Canyon) and activates its first phase of conquest: shutting down all electrical power and machinery across the globe. As the world grinds to a halt, the Venusian releases flying, leathery, bat-like synthetic creatures. These creatures attach mind-control devices into the necks of prominent local figures, effectively turning them into emotionless zombies. Among the targets is the wife of Tom's best friend and fellow scientist, Dr. Paul Nelson (Peter Graves).

Paul manages to kill one of the bat-creatures. He realizes the alien’s true intent is complete enslavement rather than salvation. When Paul's infected wife threatens him, he is forced to kill her in self-defense. Paul confronts Tom, desperately trying to strip away his delusion. Tom's rationalizations finally shatter when he discovers that his own fiercely independent wife, Claire Anderson (Beverly Garland), has taken a rifle to the alien's cave to kill the beast herself. Claire confronts the cone-shaped Venusian, killing one of its bat minions before the monster brutally kills her. Tom and Paul arrive at the cave too late to save her. Stricken with grief and horror at what his betrayal caused, Tom turns on the alien. He attacks the Venusian with a blowtorch, sacrificing his life to destroy the creature and save Earth.