This is one of several low budget films from the 1950s-1960s that share the same premise of a typically all-male expedition to a remote and isolated location were they discover a race of women without men.
Through the use of their telepathic ability the Cat-women have been subliminally controlling Helen Salinger (Marie Windsor) so she can win the navigator slot on the expedition and lead the crew to their location. Once Helen and the male members of the crew arrive on the moon the Cat-women take complete control of her mind. Unable to control the men's minds they work around this obstacle with Helen's help and the use of their superior abilities and feminine wiles. "Show us their weak points," one says to Helen. "We'll take care of the rest."
Along with telepathy, the Cat-women have the ability to transport themselves unseen from place to place within the cave. They use this ability to steal the crew's spacesuits where they were left at the mouth of the cave.
Using Helen to smooth things over after an earlier failed attack on the crew the Cat-women approach the men openly. Food and drink are brought out and a party ensues. Kip (Victor Jory) is suspicious after discovering the spacesuits are missing and confronts the Cat-women's leader Alpha (Carol Brewster) who promises to return the suits in the morning. Kip sits alone, unable to intervene while the Cat-women exploit the "weak points" of expedition commander Laird (Sonny Tufts) and the other men.
Soon the Cat-women have learned how to operate the space ship and are well on their way to success. But Lambda (Susan Morrow) falls in love with crew member Doug (William Phipps) and tells him of the plot. Carrying three spacesuits, Alpha, Beta and Helen make a break for the ship. Lambda teleports ahead to delay them and is killed by Beta (Suzanne Alexander). Kip catches up and fires several shots; Alpha and Beta are killed; Helen is uninjured. The expedition escapes and begins their return to earth.