Based on a plot bunny put up for adoption: Harry Potter, after going to the Yule Ball, keeps waking up the next morning, one week in the past. He has to find the right girl to take to the ball. It doesn't help that he's the only one who remembers.
Nine years after Harry Potter disappears from the Wizarding World, Hermione thinks she found a clue to his location. She travels halfway around the world, but is unprepared for what she finds. Story has been abandoned for a long time, but officially as of 9/22/2016. Rated M for language