Two female researchers visit a prison in the midst of the transfer of a notorious murderer for their studies on violence in men. When a mass riot breaks out at the prison, a strange phenomenon occurs revealing the women are not just researchers, but instead are Matriarchsan immortal race of women with supernatural abilities who feed on the vital force of the living. After a number of prisoners witness the duo's abilities, they find themselves at a moral crossroads between sparing the innocent or protecting their race's exposure by finishing them off.