Fear #14 (1973)

The Demon Plague! / Listen, You Fool
In the Florida Everglades, Joshua Kale and his children Jennifer and Andy watch news reports detailing the strange outbreaks of violence. Kale realizes that these seemingly unrelated incidents are in connection with the takeover of human minds and souls by demons of the underworld. He decides to assemble his cult. The cult meets in the swamp and Kale prepares a ritual that he hopes will block the demons' entry to the Earth realm.
Release Date: 1973