Set in a fictional 19th century England, is the story of Allen Walker, a 15-year-old boy who roams the earth in search of . Washed away to unknown parts of the world after The Great Flood, Innocence is the mysterious substance used to create weapons that obliterate demons known as . Hopelessly outnumbered by the Millennium Earl's forces, Lenalee, Lavi, and the rest of the survivors from Anita's ship face almost certain annihilation. Then, as if determined to make sure of it, the Noah enter the fray! But the harried agents of the Black Order refuse to throw in the towel, knowing this may be the last stand of the Exorcists. If any hope remains, it could reside with Allen Walker...but no one knows if they'll ever see him again!