Set in a fictional end of the 19th century England, it's 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 my...Set in a fictional end of the 19th century England, it's 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.