Harry Potter and the Seven Platforms

Harry Potter is going to Hogwarts, but instead of going into the Platform 9 3\4, He mistakenly goes in 10 and 3\4. He finds out, his parents are alive there, and Harry Potter can't finish Voldemort unless he finishes him from all the Platforms or he can come back. Harry Potter can keep his parents alive in the other worlds, but he has to face a lot of problems.