"Come again?" Edward said, not believing what he was hearing.

"I caught Crabbe in the hallways the previous night with it. Apparently, he was looking through your drawers for the cotton candy wrench you bought from Hogsmeade but refused to share with him. He found this instead." Lupin held up the map. "He wasn't happy when I took it from him. He was searching for the secret passage into the kitchen."

"You know how to work it?" Harry said suspiciously.

"Of course I know how to work it," said Lupin impatiently. "I helped write it. I'm Moony- that was my friends' nickname for me at school."

"The important thing is, I was watching it carefully this evening, because I had an idea that you, Ron, and Hermione might try and sneak out of the castle to visit Hagrid before his hippogriff was executed. And I was right, wasn't I?"

"You might have been wearing your father's old cloak, Harry-"

"How d'you know about the cloak?"

"The number of times I saw James disappearing under it...," said Lupin. "The point is, even if you're wearing an Invisibility Cloak, you still show up on the Marauder's Map. I watched you cross the grounds and enter Hagrid's hut. Twenty minutes later, you left Hagrid, and set off back toward the castle. But you were now accompanied by somebody else."

"What?" said Harry. "No, we weren't!"

"I couldn't believe my eyes," said Lupin, pacing, and ignoring Harry's interruption. "I thought the map must be malfunctioning. How could he be with you? And then I saw another dot, moving fast toward you, labelled Sirius Black... I saw him collide with you; I watched as he pulled two of you

into the Whomping Willow-"

"He didn't pull me in," Edward said. "I got free the last minute."

"No, Edward," said Lupin. "It was someone else."

"Do you think I could have a look at the rat?" he said evenly.

"What?" said Weasley. "What's Scabbers got to do with it?"

"Everything," said Lupin. "Could I see him, please?"

Weasley hesitated then took out the balding rat.

Lupin moved closer to Weasley. He seemed to be holding his breath as he gazed intently at the rat.

"What?" Weasley said again, holding Scabbers close to him, looking scared. "What's my rat got to do with anything?"

"That's not a rat," croaked Black suddenly.

"What d'you mean? Of course he's a rat!"

"No, he's not," said Lupin quietly. "He's a wizard."

"An Animagus," said Black, "by the name of Peter Pettigrew."

"What's that?" Edward said, at the same time Weasley cried out,

"You're both mental."

"Peter Pettigrew's dead!" said Harry, stabbing his wand at Black's direction. "He killed him twelve years ago!"

"I meant to," Black growled, his yellow teeth bared, "but little Peter got the better of me... not this time, though!"

Black made a feral sound and Edward's muscles tensed automatically. Just as the criminal lunged himself at Weasley, Edward intercepted him quickly and restrained him with his automail arm. If he wanted to act like an animal, Edward was going to treat him like one.

"Back off!" Edward growled, jabbing his arm into the man's protruding ribs. Black hissed in pain.

"Sirius, NO!" Lupin yelled. "WAIT! You can't do it just like that- they need to understand. We've got to explain."

"We can explain afterwards!" snarled Black, trying to throw Edward off. His dirty fingers were clawing at the air towards Weasley, trying to snatch the screeching rat in his hands.

"They've got a right to know -everything!" Lupin shouted. "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, though his hollowed eyes were still fixed on the rat.

"All right, then," Black said, without taking his eyes off the rat. Edward pushed him viciously away and he crumpled onto the ground.

"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," said Weasley shakily, looking round at Harry and Granger 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. Edward prepared to use alchemy but stopped himself. Lupin did not know about his alchemy yet. He could use it as an advantage when the time came.

"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!" Weasley yelled, trying to force the rat back into his front pocket, but the rat was fighting to hard. Edward moved quietly and slowly to the wall. There was a long metal pole that had broken off from the ceiling and the ends were jagged and sharp where they tore off.

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

"They didn't see what they thought they saw!" said Black savagely.

"Everyone thought Sirius killed Peter," said Lupin, nodding. "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."

The story was so stupid. They were just buying time. Edward inched closer to the wall. He was so close to Black now that he could smell him.

Then Granger spoke, in a trembling, would-be calm sort of voice, as though trying to will Lupin to talk sensibly.

"But Professor Lupin... Scabbers can't be Pettigrew... it just can't be true, you know it can't..."

"Why can't it be true?" Lupin said calmly.

"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."

Lupin started to laugh hollowly and Edward froze momentarily, wondering if he had been caught.

"Right again, Hermione!" he said. "But the Ministry never knew that here used to be three unregistered Animagi running around Hogwarts."

"If you're going to tell them the story, get a move on, Remus," said Black, who was still watching Scabbers's every desperate move. "I've waited twelve years, I'm not going to wait much longer."

"All right... but you'll need to help me, Sirius," said Lupin, I only know how it began..."

The bedroom swung open with a screech of protest. Eveoryne turned to stare at it. Lupin strode toward it and looked out into the landing.

"No one there..."

"This place is haunted!" said Weasley, trembling. Edward scoffed but he did not say anything and kept his eyes on the bedroom.

"It's not," said Lupin, 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."

Lupin pushed his graying hair out of his eyes, thought for a moment then said, "That's where all of This starts with my becoming a werewolf. None of this could have happened if I hadn't been bitten... and if I hadn't been so stupid..."

"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.

"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." Lupin paused, and looked directly at Harry.

"I told you, months ago, that the Whomping Willow was planted the year I came to Hogwarts. The truth is that it was planted because I came to Hogwarts. This house" Lupin looked miserably 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."

Edward took the chance of everyone being preoccupied with Lupin's story to move towards the wall and grab the metal pole. Inwardly, he cursed Mustang for ever making him come down to this hocus pocus place.

Before Edward could make a move towards Lupin and Black, he felt a hand underneath some kind of smooth cloth clap over his mouth. And a silent, hardly audible whisper in his ear.

"Impedimenta."