Sirius Black in Azkaban
Sirius Black sat in his lonely cell in Azkaban. He had been there for ten years for a crime he didn't commit. The crime was committed by his 'friend' Peter Pettigrew, but no one knew that except the people who knew where the Potter's were hiding before Voldemort killed them. So Sirius Black just sat there, waiting for an opportunity to escape. As he sat he thought about his godson, Harry Potter. He must think I'm evil, Sirius thought, that is, if he even knows about me. Sirius shook his head and changed his thoughts to happier thoughts. Harry would be turning eleven this year; he'd get his letter to Hogwarts and be off to magic, and friends in the common room, and complete happiness.
Sirius hadn't felt complete happiness since James and Lily Potter were alive. Two of his best friends, they had always brought the best out of Sirius. Of course he was still a prankster with James but, Lily had shown him a more serious side. He was grateful that he'd had friends like the Potter's, and because of that, not a day went by where he didn't think about them. He thought of what could have been. They would surely have more children, they'd watch Harry grow up, and go to Hogwarts. They'd help him try and find someone. They'd do whatever it took to make their loved ones happy. But all of that was ruined by Voldemort. Which is why Sirius needed to get out of Azkaban, he needed to help Harry in any way he could, and be the godfather he was supposed to be.