"Well, Harry," Sirius said. "That is a very good question. It's a long story, actually. I did not really want to get into it with you so soon, but I can understand your concern. You probably have very few memories of your parents before they died, and me too. I should have been there for you …"

Sirius's voice broke off in a choking sound, half sob. He stood up and walked over to look out at the window. Harry hated making him upset, and was wishing he had waited to ask the question. He hated to see his godfather so broken looking. He barely knew this man, but he still seemed vulnerable.

"It's okay," Harry said. "You don't need to talk about it."

"No, it's not," Sirius said fiercely, turning back around. "I should have been there for you. I can tell you did not have a good childhood just by looking at you. I know you are probably afraid of me, at least a little. I promise never to hurt you. I think I have done enough damage there."

"Really, Sirius," Harry said in protest. "It's not your fault. It doesn't matter what happened before."

"Harry," Sirius said gravely. "I made some mistakes that night. I guess I will tell you about it sometime. I blamed myself for your parents' death for a long time, and maybe I wasn't right in the head. It wasn't until recently that I managed to get out. In a way, I was always waiting for something. Then recently, I had a bit of luck. Fudge … do you know who he is?" He waited for Harry to nod. "He gave me something when visiting the prison. No one ever visited me, but for some reason he decided he needed to see me. He was not all that nice to me but he did give me a newspaper. I saw someone I had not thought of in a long time."

Sirius came closer to Harry and pulled a wadded newspaper photo out of his pocket. Apparently, he had taken to bringing the picture with him everywhere. Harry stared at it in shock.

"That's Ron," he said, staring at the worn image. "My best friend Ron, and his family."

"Hmm," Sirius said. He had a mad look in his eye that Harry did not like. "I saw that picture and knew I had to get out, no matter what. I had to catch him before he did any more harm. The article mentioned that this boy was your age."

"Catch who?" Harry asked. He needed to know what was going on. It was getting more muddled instead of clearer. He did not want to think that Ron was in danger from this man. That made no sense.

"That rat, Pettigrew," Sirius said in a low voice like a growl.

"Pettigrew? Here?" Harry asked, still not understanding.

"He's there, right there," Sirius said, practically stabbing the image. "The youngest one is holding him. That's your friend?"

"Yeah," Harry said slowly. "Wait. Hold on … holding him?"

Harry stared at the image. It was small, but he could see that Ron was holding something all right, or someone. His stomach sunk into the floor.

"Scabbers?"

"Is that what he's called?" Sirius stuffed the newspaper back into the pocket of his robes. "He's missing a toe?"

"Yeah," Harry said slowly. "How did you know …?"

"I was there," Sirius said bitterly. "I was there when he lost it. He didn't lose it, really." Sirius gave a barking laugh that was devoid of all mirth. "He cut it off, to frame me."

"What?"

"That's not a rat, Harry," Sirius said gravely. "It's a man. It's Peter Pettigrew. He's the one who betrayed your parents and why I ended up in prison." Sirius sighed. "That was my fault, really. I should never have gone after him that night. He had us all fooled. We thought he was a sniveling coward-which he is. He's just smarter than we thought."

"How can a rat be…" Harry found himself unable to finish the sentence. He suddenly remembered that some people could turn into animals. Professor McGonagall had shown them how she could turn into a cat on the first day of class. It was not something she did often, so Harry had not made the connection. "Oh, no. Ron's rat is not really a rat?"

"No, Harry," Sirius said. "I would know Peter anywhere. We used to transform … well, never mind. I do not like thinking about it. Just know that it's him. I would bet my life on it. I did, actually. I didn't know it would work, escaping from prison."

"How?" Harry asked. "How did you do it?"

"Well, Harry," Sirius said. "Peter is not the only one who can change into an animal." He backed up, held up a finger in a 'wait' gesture, and then he was gone. In his place was a rail-thin, shaggy black dog that was also huge."

"I've seen you!" Harry almost shouted. "I think I saw you … that night?"

Sirius transformed back into his also-skinny human shape and nodded. "I had to find you. I pieced enough of it together from memory and listening to people I used to know in pubs to find you. It helps that everyone was talking about my escape. They led me right to you. I've been hiding out as a dog, usually. No one knew it was me."

"That's …" Harry was at a loss for words. Finally, he just said, "You scared me." He felt a bit stupid saying that, but also could not think of anything else.

"Yeah, sorry about that," Sirius said. "I didn't mean to. I did not even mean for you to see me. I couldn't figure out why you were out at night, all alone, with your trunk. I knew something wasn't right."

"Yeah," Harry said softly. "I ran away. I got into a fight with my aunt … my uncle's sister. I just couldn't stay there anymore. And then they kicked me out. I can't go back. Not that I would ever want to."

"You'll have to tell me what that was about sometime," Sirius said gently. "You must have been very upset to run away like that. It wasn't safe."

"I know," Harry said. "At the time, where I was did not seem very safe either."

"Did they … did they hurt you? Your relatives?"

Harry did not want to answer. "Sometimes. Most of the time they just told me how much they hated me and wanted me to pretend I didn't exist."

"Oh, Harry," Sirius said, coming quietly over to him and putting his bony arm around his shoulders. "I'm so sorry. You never have to worry about that anymore. I promise I understand. My growing up was … similar. And I want you to exist. You will be with me from now on. You will be loved and cared for. I didn't get a lot of that growing up, but I want to be there for you."

"Thanks," was all Harry could think to say. This conversation was making him uncomfortable. Very few people know about what happened at the Dursleys. He did not even tell his best friends, although he knew that they already knew a lot about it. After all, Ron and his brothers had rescued Harry last summer.

"So, wait," Harry said. Thinking about Ron had returned his mind to the problem at hand. "Scabbers is not really a pet, but is a man. And you used to know him?"

Sirius nodded. He walked back to the table and sat across from Harry, their food forgotten. "They threw me in Azkaban for killing him, and a lot of muggles. In reality, Peter faked his death. He cut off his finger and threw it into the street, and then set off an explosion killing all bystanders. I didn't know he had it in him to do either. I still don't believe it. Peter was always very timid. I thought he was my friend, until your parents' death. When they were killed I realized he had betrayed us."

"How?" Harry gasped.

'It's a long story, but I guess you deserve to know what happened," Sirius said with a sigh. "Your parents had gone into hiding when they realized they were targets. There was a small group of us who were very good friends. Throughout Hogwarts there were four of us. I guess I should tell you that it was your dad, Peter, and another friend that I relied on. When we graduated we stayed close."

Your parents needed extra protection. We got help from … another person. To do a difficult spell. It's called a Fidelus and it means that no one can find you unless you tell them where you are. Your parents wanted to use me as the Secret Keeper-the person who knows the location and keeps it hidden from everyone else. As long as the Secret Keeper doesn't tell, you are safe."

"So, what went wrong?" Harry asked.

"I had a brilliant idea," Sirius repeated his mirthless barking laugh a few times. "I knew that anyone who was looking would look for me. I was the most logical choice of Secret Keeper because I was an auror and James's best friend. I convinced them to choose Peter. He was such a weak-minded person, no one would suspect him.'

"Oh, no," Harry said.

"Yes," Sirius nodded. "It was the biggest mistake of my life. I will never forgive myself. I had no idea Peter was a Death Eater, of course." At Harry's confusion, he shook his head. "A follower of Voldemort. I wanted to kill him when I realized he had betrayed us. I ran after him that night thinking you were safe. I thought I would arrest him and then come back to get you. It didn't work out that way, of course."

There was quiet descending on them, and Harry took a bite out of a sandwich. It tasted like sawdust now. The story was hard for him to swallow too. He knew it was true-his godfather had recognized the rat. It was just all too much to take in now.

"When I saw Peter in that newspaper, all I could think was that he was somehow going to get close to you," Sirius finally said.

"He has been," Harry said, almost before he realized he was speaking. "He's been close to me for two years. He sleeps in my room at Hogwarts."

Sirius nodded with a choking sound. "I will make sure he's not there anymore."

"What are you going to do?" Harry asked. "You have to catch him to clear your name?"

"Yes," Sirius said. "It will not be easy if he knows I am looking for him. The news that I escaped has not exactly been a secret."

"I can't believe he spent all of this time pretending to be a rat," Harry felt ill thinking about it. "He was pretending to be Ron's pet. Ron loves him …"

"I know," Sirius said. "It's cowardly and sick. I hate to think of a grown man pretending to be a little boy's pet." He looked up at Harry. "Has he been there all this time?"

"I don't remember," Harry said. "I know he belonged to Percy until Ron started Hogwarts. Percy got an owl and gave Ron the rat. He's had him the whole time I have known him."

"Yes, well," Sirius said. "I think that we are going to have to pretend for a while. No one can know that you are with me. I hate to think of you being anywhere near that rat, but things have to be the same in order to catch him. He is more wily than I thought, and he is going to be on alert. He knows I am looking for him."

"So, I can't tell Ron about you?" Harry realized.

"No," Sirius said. "At least not yet. We will try to take care of him soon. The sooner he is caught, the sooner I can prove my innocence and be a free man. Have you talked to Ron since he went to Egypt?"

"I tried," Harry said. "I tried to send him a letter. I did not know about Egypt. Ron's family is very poor. They never would have been able to afford a trip like that."

"It says here that they won a lottery," Sirius said, holding out the newspaper again. "I guess that's how they were able to afford it."

Staring at the picture of Ron's happy family smiling and posing in front of a pyramid, Harry just nodded. He was finding this entire story hard to believe, although he had no doubt it was true. Sirius and McGonagall could turn into a dog. Percy could have had the rat for years and passed him down to Ron, not knowing it was a man. He was sure the Weasleys had no idea. It was the perfect place to hide.

"What are we going to do?" Harry asked.

"Well, first, we are going to eat your snack and then have a good night's sleep," Sirius said. "Tomorrow we can discuss how we will approach this. Remember, though, Harry. Peter is very dangerous. He might have seemed harmless, but he has just been biding his time. Everything he has done that night and since has been planned. He is waiting for something."

"What is he waiting for?" Harry asked.

"My guess would be he is waiting for Voldemort," Sirius said. "He may know something we don't, about that night, and what happened to him. Why else would he stay in the form of a rat all this time?"