Everything belongs to J.K. Rowling!

Here is a little background story: Sirius Black fell in love with Sydney Emilia Angel, when he was 15. But later it turned out that the girl isn't other than the half-blood-sister of Augusutus Rookwood. Syd's father did everything to give his daughter a hard time. In the end he sent Sydney to the Durmstrang. However, Sydney didn't give up the fight, she had a plan to meet Sirius again... Since then Sirius finished Hogwarts and lives his own life but Sydney still didn't return...