Remus Lupin glanced up from the book in his lap—he was helping Hermione research Polysupremum—and distractedly tracked Harry's form on the broom, zipping speedily above him. Padfoot yawned lazily at his feet.

"Professor, could you get me that book—"

Lupin looked back at Hermione, "The one with the—?"

"The runes, yes," Hermione said, brushing her hair out of her face and waving distractedly in the direction of the boys' dorm.

"Of course," he said, getting up and brushing off his pants. "Pads?"

The dog in question barked in answer, and they trotted off together.

"The book with the runes," he muttered, looking around at the boys' haphazardly made beds to try and discern which one might be Ron's.

"Moony," a voice broke the stillness and Remus whipped around immediately, hand reaching for his wand, but he was too late.

The intruder wearing Sirius's body lounged seemingly lazily in the doorway, but his eyes were shrewd, and his wand, held tightly in one gloved hand, was pointed directly at Remus.

Remus lifted his empty hands, heart pounding.

"C'mere," The man said, crooking his wand ever-so-slightly to gesture for Remus to move closer. Remus did, praying that Padfoot, who had ventured outside some time ago to enjoy the open air, was safe and wouldn't return anytime soon.

"Peter," Remus whispered, his voice hoarse. He was standing directly in front of him now, and the other man crossed the remaining distance himself to press his wand directly into the center of Remus' chest.

"Pete—Is that you?" Remus asked, peering at the man's face for any sign that it was true.

The intruder grinned, toothy and small. "You always were the smart one, eh, Remus?"

Remus said nothing, his mind racing.

"Which pocket's your wand in?" Peter asked conversationally, twisting his wand slightly against Remus's chest in a vaguely threatening way.

"Left," Remus breathed, and Pete matched his stare shrewdly as he reached into Remus's pocket, making a noise of fond familiarity as he withdrew it.

"Pete," Remus said, closing his eyes, "How? They found your—"

"Finger, yes," Peter said. He transferred the willow wand to his right hand and used his teeth to tug off his left glove, revealing a naked hand with only four of Sirius's long, elegant fingers. Where the index finger should've been, there was a slim, silvery, almost fluid-looking magical prosthetic finger.

"Did you know that Polyjuice can't act on limbs that have been cursed off?" Peter asked conversationally.

Remus shook his head, feeling dizzy. "And your— your hand?" He asked haltingly.

Peter transferred the wands to his four-fingered hand, and then tugged off his second glove with his teeth, revealing the same silvery material, except this one spanned the shape of the entire hand, and was connected to a stump of a wrist.

"You always underestimated me," Peter said. "All of you, everyone. When Sirius went after me, alone, during that battle, no one thought he needed back-up. Why would he? It was just poor, fat, sniveling, wormy little Wormtail, obviously the great Sirius Black could take him blindfolded and with one hand tied behind his back!"

Remus met his gaze head on, keeping his face blank, and refused to acknowledge the twinge somewhere in the back of his head that told him he knew he had certainly been guilty of this.

"But it all worked out in my favor, in the end, a lifetime of underestimation finally worked in my favor, because when 'Sirius' finally came back, silent and moody, and all you guys found were my scattered fingers and severed hand, and so, so much blood, you didn't think twice. You all really thought he'd just ripped me apart in his magnificent fury."

"But let me tell you the truth," Wormtail hissed, a loose string of spittle flying from his lip and landing across Remus's face. Remus didn't flinch. "He was angry. He was so angry, and he couldn't see straight. I doubt he could see a thing, actually, he was crying so much, and he was stupid and he was clumsy, and he was weak, and I was sharp like a knife from fear and adrenaline, and taking him down was child's play."

Wormtail laughed, and it was manic. "You can't imagine how it felt to get away with that ruse— and for so long— and not be able to tell anyone! You all always thought I was so stupid, so weak, but let me tell you just how wrong you were." Wormtail got in his face again. "I cut off my own hand. I cut off my own fucking finger."

Remus hesitated, and then, quietly, "We never thought you were stupid, Pete."

Suddenly there was a growl from outside. A big, black, shaggy shape occupied the open doorway. Padfoot had returned.

"No, Sirius, RUN!" Remus called desperately, lurching forward, just as Padfoot took a running start, leaping at the man shaped like Sirius.

But Wormtail, impossibly, was quicker, pointing a wand each at Remus and at the flying dog, "STUPEFY!"

There was a surge of red, and then everything went black.

"I am starved," Ron announced, plopping down next to Hermione. He looked around. "Where is Professor Lupin, anyhow? Haven't seen him since breakfast."

Hermione looked up from her book briefly, her brow still creased in thought. "Hmm? Oh, I sent him to go get me a book from your dorm but that was—" she looked up at the sky, frowning, "hours ago…"

They exchanged a look as Harry dumped a stream of water from his bottle onto his face.

"S'probably nothing," Ron offered, "Maybe he wanted to take a nap or something."

"What's up?" Harry queried, joining them.

"S'nothing," Ron repeated, "Just, we haven't seen Lupin in a bit."

Harry frowned.

"Let's go to the dorm and look?" Hermione suggested. "I left a book there that I need, anyway, and the two of you should probably take a break to get some lunch, right?"

Ron's stomach growled in agreement, so they gathered up brooms and books and made their way towards the boys' lodgings.

"Did you find anything else out about the potion?" Harry asked Hermione.

"Yes, sort of," she nodded, frowning, "It's difficult because it's more ritual magic than potions science. That's a problem with these old magics; there's all these weird ingredients and steps and it's unclear whether they're actually necessary or if it's just part of the ritual."

"What kind of weird ingredients?" Ron asked.

"Well in this book it asks for 'the blood of the innocent wronged,'" Hermione sifted through the pages of a book to show them, "But does it mean the blood of an innocent person who was specifically wronged by the person performing the ritual, or will the blood of any innocent person who was wronged in any way do? And what qualifies 'wronging?' Like, maybe it just means the blood of a virgin, and the act of taking the blood is in itself the 'wronging.'" She looked up at them, huffing a sigh, "This is why I hate ritual magic," she complained, "So unspecific!"

"Why would the blood of a virgin count?" Harry frowned.

"The word 'innocent' is often a stand-in for 'virgin' in magical rituals," Hermione explained, "Which is problematic, of course, because 'virginity' itself is a social construct—"

"Do you think—" Ron interrupted, then started, glancing awkwardly at Harry, "D'you think he might be after Harry?"

Harry started, "What? Me? Why me?"

Hermione pursed her lips. "The thought crossed my mind," she admitted, "The 'innocent wronged'— who could be more innocent and wronged than the baby whose parents he betrayed? And there was that foreign magical signature that the ministry recorded near the Dursleys' place. What if he's looking for you, Harry?"

Harry thought back to his strange encounter with the man posing as Sirius Black that night after the first match, that burning sense of danger. "He definitely seemed…dangerous," Harry admitted, "There was something about him that just had me in fight-or-flight, y'know? But, I think I threw him off my scent. Lupin said I look like James, but when Sirius Black—or, whoever he is, saw me, I still had red hair, y'know, from the match, and I'd lost my glasses, so maybe I wasn't as recognizable." He paused, remembering, "And, I told him my name was Henry Weasley."

Ron nodded vigorously. "We can stick to that," He said, "I don't know if we could maintain a color change transfiguration for a long period of time, but, Hermione, didn't you mention muggles have a way of changing their hair color permanently?"

"Hair dye," Hermione answered.

"Yeah, we can dye your hair," Ron said excitedly, "I'm sure my family would stick by it if I asked them to—"

"That's not a bad idea for the short-term," Hermione said cautiously, "but I think we need a more permanent plan. We've got to figure out a way to expose the real imposter. Maybe if we change Padfoot back into Sirius—"

"You guys," Harry interrupted, stopping abruptly in his tracks. They'd reached the dorm building. "Do you feel that?" He asked, turning to Ron and Hermione.

"What?" Ron asked.

"I dunno," Harry said, feeling suddenly self-conscious as he looked back at them, "It just feels, I dunno… wrong."

Hermione regarded him carefully, and then took out her wand.

Ron did the same. "Get behind us, Harry," he instructed, holding his wand aloft and putting himself in front of Hermione.

"No," Harry said, pushing past both of them to reach the door, "He's after me, not you two."

Before either of them could protest, he thrust open the door.

Harry looked around quickly, his heart racing. Everything looked fine—messy, but that wasn't unusual— and then he caught a glance of the hastily-scrawled note that was pinned to the wall above Ron's bunk with one of Dean's darts.

Harry Potter—

I have your wolf and your dog. Come and get them. Come alone.

Harry reached blindly for the note, his heart thudding.

"HARRY NO!" Hermione screamed in warning, "It could be a—"

Harry felt someone grab his shoulder as his fingers touched the note.

There was a tugging on his navel and a whoosh; his surroundings blurred. He felt suddenly like his feet had left the ground, like he was moving through space at an incredible speed, the world around him spinning. All he could do was cling blindly to the note; the hand on his shoulder dug painfully into his skin.

And suddenly it was all over. He fell with an ungraceful thud, and with an "oof" the person who'd clung to his shoulder—Ron, he realized— and another body—possibly Hermione, clinging to Ron's hand—collapsed on top of him in a heap.

"—Portkey," Hermione's voice finished with a sigh.