Peter Pettigrew, the wizard Black supposedly murdered all those years ago... It took a while for that to register with Jade, she'd known Scabbers since she came to Hogwarts. Now, Professor Lupin and Sirius Black were saying that Scabbers was not Scabbers and he wasn't a rat at all. He was a wizard, he was Peter Pettigrew.

"You're both mental." Ron scoffed.

"Ridiculous!" Hermione agreed.

"Peter Pettigrew's dead!" Harry argued, he was still angry but not nearly as much as he had been before Professor Lupin came. "He killed him twelve years ago!" He pointed at Black, whose face darkened.

"I meant to." He growled, his yellow teeth bared. "But little Peter got the better of me… not this time, though!" Sirius Black lunged for the rat in Ron's hands. Ron cried out as Black's weight fell on his broken leg.

"Sirius, no!" Lupin yelled, launching himself forwards and dragging Black away from Ron again, "Wait! You can't do it just like that. They need to understand. We've got to explain-"

"We can explain afterwards!" Black snarled, trying to throw Lupin off. There they went again with the vagueness. Scabbers was going crazy in Ron's grasp, freaking out and scratching at Ron's face to try and get away from them.

"They've got a right to know everything!" Lupin panted, still trying to restrain Black. "Ron's kept him as a pet! There are parts of it even I don't understand... and Harry, you owe Harry the truth, Sirius!" Black stopped struggling at that, he calmed down even though he kept his eyes on Scabbers.

"All right then. Tell them whatever you like. But make it quick, Remus. I want to commit the murder I was imprisoned for."

"You're nutters, both of you," Ron said shakily, he looked around at his other friends for support. "I've had enough of this. I'm off." He tried to heave himself up on his good leg, but Lupin raised his wand again, pointing it at Scabbers. Jade and Hermione instinctively stepped a little in front of Ron, blocking Lupin's target.

"You're going to hear me out, Ron," He said quietly. "Just keep a tight hold on Peter while you listen."

"He's not Peter, he's Scabbers!" Ron yelled, trying to force the rat back into his front pocket, but Scabbers was fighting too hard. Ron swayed and Hermione caught him and helped him ease back down on the bed.

"There were witnesses who saw Pettigrew die," Harry said slowly. "A whole street full of them."

"They didn't see what they thought they saw!" Black growled, still watching Scabbers struggling in Ron's hands.

"Everyone thought Sirius killed Peter." Lupin nodded. "I believed it myself until I saw the map tonight. Because the Marauder's map never lies… Peter's alive. Ron's holding him, Harry." Harry took his eyes off of Black and looked down at Ron. Ron and Harry locked eyes and something happened between them that Jade noticed.

"But, Professor Lupin…" Hermione began slowly, "Scabbers can't be Pettigrew. It just can't be true, you know it can't."

"Why can't it be true?" Lupin asked calmly, like he often challenged students' reasoning in class.

"Because… because people would know if Peter Pettigrew had been an Animagus. We did Animagi in class with Professor McGonagall. And I looked them up when I did my homework. The Ministry of Magic keeps tabs on witches and wizards who can become animals. There's a register showing what animal they become, and their markings and things… and I went and looked Professor McGonagall up on the register, and there have been only seven Animagi this century, and Pettigrew's name wasn't on the list." This was one of the moments when Jade was glad Hermione was a know it all. Professor Lupin started to laugh.

"Right again, Hermione!" He smiled. "But the Ministry never knew that there used to be three unregistered Animagi running around Hogwarts."

"If you're going to tell them the story, get a move on, Remus." Black urged him on. "I've waited twelve years, I'm not going to wait much longer."

"All right… but you'll need to help me, Sirius. I only know how it began-" Lupin broke off. There had been a loud creak behind him that caught everyone's attention. The bedroom door opened wide on its own. Lupin strode toward it and popped his head out onto the landing. "No one there."

"This place is haunted!" Ron cried.

"It's not," Lupin sighed, still looking at the door in a puzzled way. "The Shrieking Shack was never haunted… the screams and howls the villagers used to hear were made by me. That's where all of this starts, with me becoming a werewolf. None of this could have happened if I hadn't been bitter… and if I hadn't been so foolhardy…" Professor Lupin looked tired. They were all tired, it was starting to get late and the only thing keeping Jade going was her adrenaline. Ron started to interrupt, but Hermione shushed him. "I was a very small boy when I received the bite. My parents tried everything, but in those days there was no cure. The potion that Professor Snape has been making for me is a very recent discovery. It makes me safe, you see. As long as I take it in the week, preceding the full moon, I keep my mind when I transform… I'm able to curl up in my office, a harmless wolf, and wait for the moon to wane again." Professor Snape had been helping him? It was hard for Jade to believe, she couldn't imagine Snape helping anybody. "Before the Wolfsbane Potion was discovered, however, I became a fully-fledged monster once a month. It seemed impossible that I would be able to come to Hogwarts. Other parents weren't likely to want their children exposed to me. But then Dumbledore became Headmaster, and he was sympathetic. He said that as long as we took certain precautions, there was no reason I shouldn't come to school." The storytime was fascinating but Jade wished he would quickly get to the point. "I told you, months ago, that the Whomping Willow was planted the year I came to Hogwarts," Lupin told Harry. "The truth is that it was planted because I came to Hogwarts. This house," Lupin signaled around the room. "The tunnel that leads to it, they were built for my use. Once a month, I was smuggled out of the castle, into this place, to transform. The tree was placed at the tunnel mouth to stop anyone coming across me while I was dangerous." Jade was rather impressed by the lengths Dumbledore had gone to to make Professor Lupin comfortable and yet keep the other students safe. "My transformations in those days were... were terrible. It is very painful to turn into a werewolf. I was separated from humans to bite, so I bit and scratched myself instead. The villagers heard the noise and the screaming and thought they were hearing particularly violent spirits. Dumbledore encouraged the rumor… even now, when the house has been silent for years, the villagers don't dare approach it…" None of it was real, the legend of the Shrieking Shack was fake, not that the villagers of Hogsmeade knew, but it cleared up the mystery of the ghoulish-looking house. "But apart from my transformations, I was happier than I had ever been in my life. For the first time ever, I had friends, three great friends. Sirius Black… Peter Pettigrew… and, of course, your father, Harry. James Potter." Harry was listening intently, he was rigid but he had lowered his wand. "Now, my three friends could hardly fail to notice that I disappeared once a month. I made up all sorts of stories. I told them my mother was ill, and that I had to go home to see her… I was terrified they would desert me the moment they found out what I was. But of course, they, like you, Hermione, worked out the truth…" Hermione flushed under his gaze. "And they didn't desert me at all. Instead, they did something for me that would make my transformations not only bearable, but the best times of my life. They became Animagi."

"My dad too?" Harry asked, astonishment lightening his voice.

"Yes, indeed," Lupin nodded. "It took them the best part of three years to work out how to do it. Your father and Sirius here were the cleverest students in the school, and lucky they were because the Animagus transformation can go horribly wrong, one reason the Ministry keeps a close watch on those attempting to do it. Peter needed all the help he could get from James and Sirius. Finally, in our fifth year, they managed it. They could each turn into a different animal at will."

"But how did that help you?" Hermione asked.

"They couldn't keep me company as humans, so they kept me company as animals," Lupin clarified. "A werewolf is only a danger to people. They sneaked out of the castle every month under James's Invisibility Cloak. They transformed… Peter, as the smallest, could slip beneath the Willow's attacking branches and touch the knot that freezes it. They would then slip down the tunnel and join me. Under their influence, I became less dangerous. My body was still wolfish, but my mind seemed to become less so while I was with them."

"Hurry up, Remus." Black snarled, not enjoying the trip down memory lane and ruining the experience for the four of them.

"I'm getting there, Sirius, I'm getting there." Lupin went on to tell them how he and his friends soon left behind the Shrieking Shack and ran through the grounds and Hogsmeade village during the night, seeing everything there was to offer and then creating the Marauder's map.

"What sort of animal-" Harry began, but Hermione cut him off.

"That was still really dangerous! Running around in the dark with a werewolf! What if you'd given the others the slip, and bitten somebody?"

"The thought that still haunts me, and there were near misses, many of them. We laughed about them afterwards. We were young, thoughtless… carried away with our own cleverness." It would be inappropriate to say so but it did sound like fun. "I sometimes felt guilty about betraying Dumbledore's trust, of course. He had admitted me to Hogwarts when no other headmaster would have done so and he had no idea I was breaking the rules he had set down for my own and others' safety. He never knew I had led three fellow students into becoming Animagi illegally. But I always managed to forget my guilty feelings every time we sat down to plan our next month's adventure. And I haven't changed." Lupin's face had hardened then, "All this year, I have been battling with myself, wondering whether I should tell Dumbledore that Sirius was an Animagus. But I didn't do it. Why? Because I was too cowardly. It would have meant admitting that I'd betrayed his trust while I was at school, admitting that I'd led others along with me… and Dumbledore's trust has meant everything to me. He let me into Hogwarts as a boy, and he gave me a job when I have been shunned all my adult life, unable to find paid work because of what I am. And so I convinced myself that Sirius was getting into the school using dark arts he learned from Voldemort, that being an Animagus had nothing to do with it… so, in a way, Snape's been right about me all along."

"Snape?" Black scoffed, "What's Snape got to do with it?"

"He's here, Sirius," Lupin said. "He's teaching here as well." He looked away from Black and at the four children in front of him. "Professor Snape was at school with us. He fought very hard against my appointment to the Defense Against the Dark Arts job. He has been telling Dumbledore all year that I am not to be trusted. He has his reasons… you see, Sirius here played a trick on him which nearly killed him, a trick which involved me-" Black barked out a humorless laugh.

"It served him right," He sneered. "Sneaking around, trying to find out what we were up to… hoping he could get us expelled..."

"Doesn't mean you plan a prank that could kill him!" Jade said obviously. Black looked at her again as if he were trying to place her face somewhere he'd seen before. Jade quickly looked away, uncomfortable from his close inspection.

"Severus was very interested in where I went every month." Lupin continued. "We were in the same year, you know, and we... didn't like each other very much. He especially disliked James. Jealous, I think, of James' talent on the Quidditch field…" Jade cast a look at Harry but he was listening with undivided attention. "Anyway, Snape had seen me crossing the grounds with Madam Pomfrey one evening as she led me toward the Whomping Willow to transform. Sirius thought it would be amusing to tell Snape all he had to do was prod the knot on the tree trunk with a long stick, and he'd be able to get in after me. Well, of course, Snape tried it, if he'd got as far as this house, he'd have met a fully grown werewolf. But your father, who'd heard what Sirius had done, went after Snape and pulled him back, at great risk to his life." Jade knew this part of the story, Harry had told her about it earlier in the dungeons, but she didn't know the details. "Snape saw me, though, at the end of the tunnel. He was forbidden by Dumbledore to tell anybody, but from that time on he knew what I was."

"So that's why Snape doesn't like you." Harry started slowly, "Because he thought you were in on the joke?"

"That's right." A cold voice drawled from the wall behind Lupin, Jade knew that voice, but no one was standing there. Professor Snape pulled off the Invisibility Cloak with one swift motion, his wand pointing directly at Lupin.