In the heart of the Midwest, an extraterrestrial invasion takes hold, as mysterious beings infiltrate human minds to assert their dominance. A trio of brave operatives from a government agency, comprising Sam and Andrew Nivens, along with Mary Sefton, must band together to thwart the alien threat and prevent their own minds from being taken over.

The Puppet Masters
Alien slugs, resembling stingrays, invade Earth by attaching themselves to humans' backs, controlling their minds through a terrifying parasitic takeover.