A scientist, Dr Holander, takes his niece Miranda to Mexico in an attempt to reverse the effects of the alien DNA he used to create her. However the treatment goes horribly wrong, and sets Miranda on a killing spree as she sets out to find a mate.
When she reaches the end of her lifespan, a scientist rushes to Mexico, in order to save the half-breed alien seductress he raised as his docile niece, but soon awakens the deadly, sexual predator inside her.