Alus and Arek-the Twins, demons molded by Satan to embody their respective sins of Gluttony & Greed-have a problem. A seemingly normal human girl appears to hold a strange power over them, something they've never before experienced in their collective millennia on Earth. To try and puzzle it out, they call upon their unlikely sister Runeak, Wrath herself, to help. In a series of introspective and sometimes surprising events, the Twins to discover more about themselves, each other, and their commitment to their mission-to harvest souls for the Devil Itself.