Based on the graphic novel Phantom of Inferno, this gritty anime series follows a young man who stumbles into a violent rivalry in the American underworld and ends up being abducted and reprogrammed as an assassin by the Inferno syndicate. Renamed Zwei, he plunges into a new life of cold-blooded killing, obeying orders without question. When Zwei comes into contact with Ein, another of Inferno’s brainwashed assassins, they begin a friendship.