A young woman from Berkely and her boyfriend go on a picnic and end up at an aging spa resort located in the treeless hills to the southeast of the Bay Area. They encounter an elderly resident there (Edna MacAfee), but something feels off, possibly even threatening. “Warlock Moon” (1973) initially evokes elements of “Night of the Living Dead,” before developing similarities to "Let’s Scare Jessica to Death" and "N…