Dr. Jonas Temple, geologists, and his assistant Laurie have been examining some unusual rocks which seem unlike any they have studied. Later, when Temple is alone, the rocks assume the forms of black, living, pulsating creatures that slither across the cabinet and forcefully enter Temple’s body as he struggles for his life. They are creatures from another palner who wish to take over Earth by using human bodies as their hosts. Laurie’s husband Dr. Cameron, has a metal plate in his head and he can hear the creatures talking. Thinking he is suffering brain damage and going insane he takes Laurie on a trip, but Temple, doing the bidding of the rock creature inside him, follows them to kill Cameron because Cameron knows their secret.
