“Vengeance is sweet…” Snape said in a cold voice. “How I hoped I would catch you. And you, Lupin…”

“Severus…”

But Snape silenced him by pointing his wand at him.

“I told Dumbledore you were helping your old friend into the castle and now, here’s the proof.”

“Brilliant Snape. As usual you put your penetrating mind to the task and come to the wrong conclusion.” Black said. “Now, do excuse us, Remus and I are busy, we have some unfinished business to attend to…”

Snape pressed his wand to Black’s throat, a look of pure loathing on his face.

“Severus, don’t be a fool.” Lupin said calmly.

“Can’t help it, it’s habit,” Black said.

“Sirius, be quiet, –”

“Be quiet yourself, Remus!”

Snape sneered smugly.

“You two never change, bickering like an old married couple.”

“Oh, why don’t you run along and play with your chemistry set!” Snape snapped.

“… I could kill you now…” Snape said. “But why deny the Dementors…”

Sirius went even paler. Megan and the others stood frozen, unsure what to do or say. Snape, on the other hand was eyeing Sirius with suppressed triumph.

“Yes, the Dementors’ kiss… one may only imagine what that can be like to endure…”

“Sir, if you just hear them out–” Megan said, trying to be cordial.

“SILENCE!” he yelled. “You and your pathetic friends are already facing long overdue expulsion from Hogwarts–”

“Severus, really!” Lupin interjected, shocked.

“As are you, Lupin.” He added icily, his wand slashing the air to point at his chest. “I knew you couldn’t be trusted. Dumbledore was so convinced you were harmless…”

“STOP IT!” Megan yelled. “Just because they played a trick on you as teenagers, in which, by the way professor Lupin had no involvement, you won’t even listen!”

“I won’t be spoken to like that, Potter, now move!” Snape said, now pointing his wand at Megan.

“Severus, what are you doing?!” Lupin exclaimed in alarm. “Lower your wand at once!”

“Don’t you dare, Snape!” Black suddenly shouted, now free of Snape’s wand.

He shoved Snape backwards and bounded in front of Megan just as Cedric moved to do the same. Megan again recognised the scene from her exam.

“You’re letting a schoolboy grudge cloud your reason,” Lupin said.

Megan glanced at Snape who had a mad glint in his eyes she had never seen before. He waved his wand. Black pushed Megan and Cedric backwards as thin ropes tied themselves around him and then Lupin. But Megan wanted to hear them out, so she whipped out her wand, pointed it at Snape and shouted:

“Expelliarmus!”

He flew backwards and slumped to the floor.

“Megan, what did you do?” Harry asked. “You attacked a teacher!”

Megan dropped to her knees and unbound Lupin who then did the same for Sirius.

“Should have left him to me.” Black said, looking at Megan.

When she looked into his eyes, she didn’t feel scared, for some reason, like some instinct was telling her he wasn’t bad…

“I still don’t know if I believe you.” Megan said.

“Then, let us show you.” Lupin said. “Ron, may I see Scabbers?”

“… No! He’s my rat, he’s not some animathingy! There are millions of rats, how d’you know it was this one?”

“That’s actually a fair question, Sirius.” Lupin said, turning to Black.

Black pulled out a crumpled piece of paper and showed it to him. Megan stepped forwards to peer at it too, and recognised the picture.

“That’s when Ron’s family went to Egypt…” She frowned. “How does that prove anything?”

“Look at the rat.” Black said.

Megan and Lupin peered at Scabbers, sitting on Ron’s shoulder. Sure enough, he had a missing toe.

“Fudge came to inspect Azkaban last summer,” Black said. “And he had this clipping. I knew him at once from the hundreds of times I’d seen him transform… And the article said he was going to Hogwarts. To where Megan was. I immediately knew I had to get him before he got to her. If one single hint of Voldemort’s return reached his ears, he could strike without anyone being able to stop him.”

“… So… you never intended on killing Megan?” Hermione asked.

“Kill her? Heavens, no!” Black said in disgust. “I was trying to protect her.”

“Didn’t you ever wonder why Scabbers was living so long?” Lupin asked Ron.

“Cause we took care of him!” Ron said.

“Not looking so good at the moment, though, is he?”

“You mean you weren’t here to kill me but him?” Megan asked.

“Yes.” Black said flatly.

“But I still don’t understand how you can be innocent; you were their Secret Keeper! They trusted you above all! You were the only one who could have betrayed them!”

Black’s cold face suddenly showed unmeasurable grief.

“I as good as killed them… I know that.” He said sadly. “But that’s the key point of the whole story. I wasn’t their Secret Keeper. Everyone knew how close James and I were. So I knew I would be the most likely target to look for them.”

Megan’s mouth fell open in understanding.

“… You switched places….” she realised. “You made Pettigrew Keeper instead of you…”

Sirius nodded.

“A mistake I will regret for the rest of my life.” He said heavily.

“You never told me…” Lupin said dumbstruck.

“The fewer knew, the better. Dumbledore was adamant there was a traitor in our close circle.” Black said.

“The best way to find out is to see if that rat is really a rat.” Lupin said.

He turned to Ron.

“Just let me have him a moment,” Lupin said. “If he really is a rat, then no harm will come to him.”

Megan watched as Lupin took a squealing and wriggling Scabbers from Ron.

“Ready?”

“I’ve been ready for twelve years…” Black said.

Lupin put Scabbers on the table. Immediately, he scurried away. Black and Lupin shouted as one:

“Homorphus!”

And as Scabbers jumped, he became larger and his paws became feet as he crashed into the wall. Immediately, Black and Lupin pulled him out of the debris.

“Why, hello, Peter, long time no see.” Lupin said coldly.

Pettigrew was the man Megan had seen in her vision.

Pettigrew looked wildly around, his eyes wide. He was small and twitchy, his face like a rat's, with claw-like nails and a mucky face.

“Remus…? Sirius… my old friends!”

He tried to go forwards but they pushed him back. His eyes then fell on Megan who had stepped back.

“Megan, look at you, all grown up…!” he said, stepping towards her. “You look a lot like your parents… we were the best of friends!”

“How dare you speak to Megan!” Snarled Black, yanking him away. “How dare you talk about Lily and James in front of her!”

“You sold them to Voldemort, did you not?” Lupin asked coldly.

“… Do… don’t know what you mean, Remus…” Pettigrew said. “Is that what Sirius said? You don’t believe him, do you, he tried to kill me! He’s here to try again!”

“No one will kill anyone until we have cleared this up. Did you or did you not disclose where Lily and James were hiding, with their baby, to Voldemort?”

Peter looked as though he was struggling with himself.

“But if he was working for Voldemort,” Harry put in. “Why didn’t he act then…? He’s been near Megan for nearly three years!”

“Exactly! See, I can’t possibly be the one!” Pettigrew squealed.

“Because he was waiting to make sure Voldemort was fully back and the biggest bully in the playground.” Black said disgustedly. “Why else choose a wizard family? He was keeping an ear open for information. You always wanted big friends, didn’t you? I don’t know how I didn’t see through you before… you were exactly the same in school… we were the big boys that kept you safe.”

“No, never!” Pettigrew squeaked. “Remus, you believe me, don’t you, old friend…”

“I have to admit it sounds strange to me that an innocent man would spend twelve years as a rat.” Lupin said calmly.

“Innocent but scared!” the little man whined. “Because I had sent the Dark Lord’s spy, Sirius Black, to Azkaban!”

“LIAR!” Black yelled. “You passed him information for an entire year before they were killed! How dare you insult me by calling me a spy for Voldemort!”

“But I never…!”

“You became Secret Keeper on my request, and my request alone!” Black snarled. “I thought it was perfect. He would come after me and leave the real Secret Keeper safe. Who would suspect a talentless, weak thing like you with me or even Remus? How else would Lily and James have been found and killed, with Megan almost suffering the same fate?! Did it ever cross your mind that that monster was ready to kill an infant, when you betrayed the Potters?!”

Megan then voiced something:

“… But… Sirius… if you don’t mind my asking, how did you get out of Azkaban, if not by use of Dark magic?”

He looked at her, pondering.

“I’m not sure how… I think the conviction I was innocent was what kept me sane for all those years. And when it became too much, I would become a dog since the Dementors can’t see. And when I heard about Peter… I knew I had to act.”

Megan then remembered Mr Weasley saying he had been muttering in his sleep “At Hogwarts…”…

“And it became an obsession. Since it wasn’t happy, the Dementors couldn’t take it, and it cleared my mind. So one night, I slipped out as they were bringing my food. Then I swam back to the mainland and made my way to Hogwarts. I hid in the forest. But I did come out to watch Quidditch. You’re truly your father’s daughter, Megan. You’re as good as he was on a broom.”

Megan and he exchanged another look.

“You must believe me.” He said in croaky voice, as though this mattered more than his own life. “I never betrayed them. I loved you all too much. I would have died first.”

Megan finally believed him. One point clinched it. Black and Lupin referred to Voldemort by his name while Pettigrew used the terms of Dark Lord, which implied some sort of connection between them. She glanced at her friends, in case they had doubts. But they didn’t. She turned to Black, and nodded.

“No, I beg you!” Pettigrew screamed. “I… Remus! You never knew of the switch! Why didn’t Sirius tell you?”

“He wouldn’t if he thought I was the spy,” Lupin said evenly. “I assume that’s why you never told me?”

“Forgive me, Remus.” Black said. “It was not against you.”

“Not at all, Padfoot, my old friend.” Lupin replied. “You will, I hope, in turn forgive me for thinking you too were the spy?”

“Naturally.” Black nodded. “But I want to know, Peter. Why? We were your friends, your brothers. You betrayed them, and almost caused the death of an innocent child! Do you even realise it? Megan was barely one year old!”

“I didn’t mean to…!” he wailed. “The Dark Lord… you have no idea what powers he has…! He would have killed me! Ask yourself Sirius: what would you have done?”

“I would have died, you treacherous piece of filth!” Black shouted. ”I would have given my life for them, and you! We all would have! All but you!”

Just then, Pettigrew bolted for the door. Megan hurried in front of him to block his path. He gripped her jacket and leaned in, his stench filling Megan’s nose.

“Your dad wouldn’t have wanted me dead, Megan!” he wheezed in her ear. “James would have shown me mercy…!”

“Get off her, you dirty rat!” Black growled fiercely.

Black and Lupin pulled him back and pointed their wands at him.

“You should have realised, Peter,” Lupin said fiercely, “that if Voldemort didn’t kill you, we would. Together!”’

Megan then darted forwards.

“No!” she called.

She stood before Pettigrew, wands pointing at her.

“You can’t kill him,” she said, looking into their eyes.

“Megan, this piece of filth is the reason you never got the life you deserved.” Black said in disbelief, staring darkly at Pettigrew, cowering on the floor.

“I know what he is.” Megan said. “But he can go to the castle.”

“Oh, Megan…! Thank you…!” Pettigrew gasped, crawling towards her.

“Get off,” she said stepping back. “I said you could go to the castle. Then, the Dementors can take you.”

His gasping turned to pathetic sobbing.

“You alone have the right to decide.” Black said. “But think about what he did…”

“If we choose to kill him, we’ll be no better than him or Voldemort.” Megan said. “If anyone deserves to go to Azkaban, it’s him.”

“All right. You can move, Megan.”

She frowned, hesitating.

“I’m just going to tie him up, I swear,” he said.

She stepped aside.

“But if you transform, Peter, we will kill you.” Lupin said. “Agreed, Megan?”

Megan looked at Pettigrew so she knew he could see her, and nodded.