Percy and Harry Potter share a universe and until Harry turns eleven his life is mostly the same as in the books, and Percy's life is completely different than in the books. Sally Jackson is a witch and a demigod daughter of Athena. The Potters are friends with Sally too. Harry lives with his parents because they are not dead. I do not own the characters from Harry Potter or Percy Jackson, but the authors that do own them, are J.K Rowling and Rick Riordan. A new metal is described in this book.