The end of the 20th century. A few years ago, when she was still a girl, Sir Integra Hellsing inherited her father's leadership of the secret Hellsing organization, which has been protecting Britain from the undead for over a century, and became the mistress of the tamed super-vampire Alucard. After another cleanup, Integra notices that the number of spontaneous vampires and zombies has increased significantly, as the 13th Department of the Vatican, Iscariot, consisting of battle mages led by Paladin Alexander Anderson, and the secret organization Millennium, confront Hellsing.