Sirius Black meets Isabella Hart, the new girl at Hogwarts who has had a bad year. She was expelled from her school in NY, and her dad moved her family to England to live with his horrible sister. Sirius sticks by her, and helps her along the way.

over used plot, but my take on it. Harry and Ginny go to a new universe where that Harry was a death eater. They have to come up with disguises to fit in, but how will everything turn out?