Dr Hess Green [Duane Jones], anthropologist and geologist, is studying the Myrthian culture of Nigeria. Myrthians were human blood drinkers. Green gets a strange dagger from Myrthia and asks research assistant George Meda [Bill Gunn] to help him. When Meda stabs Green with the dagger (Why? "Oh, he's freaking out again"), Green doesn't die; he becomes immortal and needs to drink human blood. When Meda's wife [Marlene Clark] comes looking for Meda, she falls in love with Green. And when she finds her husband's body in Green's freezer, she marries Green!!!! Green makes Mrs. Meda immortal, then goes to a revivalist church to save himself. It's a screwy life being a Myrthian vampire, I guess.