Everything changed on the wild camping trip the Dursleys went on - forced to take Harry with them. It was supposed to be an opportunity to bond with Vernon's boss. They didn't know they were walking right into the territory of something deadly. None of them would make it back. (Rating subject to change. Kid!Harry)
Harry dies long before his time. He meets the Red Lady, who informs him that there was more to his mother's death than just a love filled sacrifice; she agreed to share herself with a demonic being- she also promised Harry upon his death. But he is still at the whims of Fate and prophecy- of course, he can always do both. (Amoral!Harry)
In his 4th Year in Hogwarts, the day before the Tri-Wizard champions are picked, Harry comes across a mysterious magical artefact that forces his mind and body into that of a young child. He's stuck like that, until he succeeds in passing the unknown requirements needed to transform him back. Everyone else is left scrambling to protect him from the deadly tasks ahead.