"Luna Lovegood gave me the Ravenclaw list." Hermione looked up from the parchment with curiosity. "When did you become acquainted with her?"
"I don't know her, really. We have a mutual friend." Draco was only half-listening. His eyes were on the window, or rather on nothing at all—he was somewhere else entirely, turning the same problem over in his mind for the fourth time that morning. "Good thing I thought to ask her."
"I've been going through the names the way you suggested," Hermione said, flipping through the list. "Do you want to look over what I've marked so far?"
"Yes, that's good—" He rested his chin on his hand and gazed out at the snow-covered grounds.
He hadn't glanced at the list once.
Hermione studied him for a moment, then looked out the window herself. There was nothing there. Just snow.
She set down the parchment rather firmly. "Draco. What is going on with you?" She kept her voice low, though around them the Transfiguration classroom was filling up and nobody was paying attention to the front row. "You've been like this since Christmas. You're somewhere else entirely, every single day."
"I'm thinking through something," he said, without turning from the window. "A problem I can't quite solve."
Behind them, at a careful distance, Neville was attempting to hold back Susan Bones, who had noticed the tension and was considering intervention.
"Don't," Neville said, in an urgent undertone. "They've been like this since before the holidays. You'll get caught in the middle."
"But what if she needs—"
"Hermione doesn't need rescuing," Neville said, with the resigned authority of someone who has watched this dynamic play out many times. "She always wins. Then Malfoy goes cold with everyone else for a week. Meaning me, mostly."
"She actually defended him in the library, you know," Susan whispered.
"I know." Neville watched the front row with mild trepidation. "That doesn't make any of this less alarming."
Hermione, unaware that she had an audience, had softened slightly at Draco's admission. He looked genuinely troubled—not evasive in the way he sometimes was, but actually stuck.
"What's the problem?" she asked. "Tell me. I might be able to help."
He sighed.
"I doubt it," he said. "Unless you know a way to keep someone invisibly close to another person—close enough to watch them, close enough to act if necessary—without anyone noticing."
Hermione considered this properly. "The Invisibility Cloak?"
"No. It doesn't involve a Cloak."
"Polyjuice Potion?"
"Not that either."
She frowned, turning the problem over. "Well," she said finally, "it sounds a bit like something from a Muggle fairy tale, actually. Thumbelina. She's small enough to fit in a pocket—completely invisible to anyone who isn't looking for her."
"Thumbelina," Draco repeated, as though tasting the word.
"It's a children's story. She escapes various unpleasant fates through the whole thing—toads, moles, field mice who want to marry her off—and in the end she's rescued by a prince." Hermione's expression became briefly disapproving. "Which I always found rather unsatisfying. After all that, she still needs someone else to save her."
"She could have just stayed where she was," Draco said, distantly.
"Exactly." Hermione looked at him. "Though you're clearly not thinking about Thumbelina."
She was right. He was staring at her—not at her, precisely, but through her, in the way of someone whose thoughts had just turned a corner and were running somewhere new.
She shifted slightly under the scrutiny. "What?"
"Nothing," Draco said. "I was just thinking."
The school bell rang. Professor McGonagall had not yet appeared. Harry and Ron arrived last, sliding into their seats, slightly out of breath.
"Thank Merlin," Ron said, looking around at the empty podium with relief.
The tabby cat sitting on it blinked once, then stepped off the edge, and in the instant before it landed it was no longer a cat.
"Brilliant," Ron said, in a tone of involuntary awe.
"I'm glad the transformation meets with your approval, Mr. Weasley," Professor McGonagall said, in a tone suggesting that his approval was nice but beside the point. "Though I would still appreciate an explanation for why you and Mr. Potter were late."
"We misread the time," Harry said.
"Perhaps I ought to Transfigure you both into a clock," she said, and pointed them toward their seats.
She was still visibly displeased—particularly when Ron pulled his rat from his pocket and deposited it on the desk with the casual air of someone unaware this might be objectionable. Professor McGonagall looked at the animal with the pained expression of a woman who has said something about this before.
"Mr. Weasley. Producing a Transfigured mouse with the tail still attached, as you did last lesson, is not a successful result. Please give that animal some proper attention rather than using your practice time to make it look worse."
Ron nodded, looking guiltily at Scabbers.
"She is extraordinary," Hermione murmured to Draco. "There are only seven registered Animagi in the wizarding world at present, and she's—"
"Animagus," Draco said, in a tone that was not quiet at all.
The classroom looked at him. Professor McGonagall looked at him.
"Mr. Malfoy," she said, with precision. "Was there something you wished to add?"
"Only that the transformation was remarkable, Professor." He recovered smoothly, settling into the characteristic Malfoy cadence. "I was simply expressing admiration."
"If you applied the energy you spend on flattery to your practical work, Mr. Malfoy, you might one day attempt a transformation of your own." She turned back to the board, apparently deciding not to pursue it. "You may all begin."
Draco sat back and looked—with calm, focused, undisguised interest—at the rat sleeping on Ron's desk.
If Rita Skeeter could conceal herself as an unregistered Animagus for years, moving through closed rooms, attending private conversations, gathering everything she needed for her articles—then it was not impossible that someone else might do the same thing.
Someone who needed to disappear.
Someone who needed to be close, to be overlooked, to be considered harmless.
"What is it?" Hermione asked, watching him.
"I've just made rather a significant realisation," he said, and a smile crossed his face that he didn't entirely bother to suppress.
"About what?"
He pressed one finger to his lips and glanced at the rat.
Hermione followed his gaze. She looked back at him with a baffled expression.
He mouthed: later.
She mouthed back: you are extremely aggravating.
He smiled properly this time, and returned to watching the rat with the patient attention of someone who has all the time he needs.
---
He found the Weasley twins in the corridor after class, holding court with Lee Jordan on the subject of something involving spiders. They spotted Draco approaching and turned with identical expressions of interested speculation.
"The young Malfoy," Fred said cheerfully. "Buying in bulk today?"
"Something like that," Draco said. "Can we find somewhere quieter?"
They made their excuses to Lee Jordan, exchanged a glance with each other, and followed him into the nearest empty classroom.
They dropped into chairs at the front as though they'd been asked here for a meeting they'd already half-anticipated.
"Ron's rat," Draco said.
Fred raised an eyebrow. "The bald one?"
"Yes."
"Now there's an unexpected opening," George said, with mild fascination. "What about it?"
"How long has it been in your household?"
They looked at each other.
"Oh, years," Fred said. "Percy had it first. Must be getting on for twelve years now, actually—"
"Eleven," George corrected. "Ron was about one when Mum got it."
Draco had already been calculating. 1981. The year Harry's parents were killed, the year Peter Pettigrew had staged his own death and vanished, the year Sirius Black had been sent to Azkaban for a murder that amounted to a missing finger and a pile of dead Muggles.
The year a rat had arrived at the Weasley household and never left.
"Don't you think eleven years is rather a long time for a rat?" Draco said.
George tilted his head. "We did always wonder."
"We assumed Percy overfed it," Fred said. "Or Ron."
Draco pressed his fingers briefly to his face.
"Have either of you noticed," he said, with care, "that it's missing a toe?"
A pause.
"Percy always said he'd done it by accident," George said, more slowly now. "One of the practice Transfigurations in first year."
"Right." Draco looked at both of them. "I want to tell you something. I need you to hear it seriously, and I need you not to mention it to Ron."
The twins exchanged another look. Whatever remained of the performance dropped away.
"Go on," Fred said.
"I think that rat is an unregistered Animagus. I think it's been using your family as cover for eleven years." Draco kept his voice even. "I think it's Peter Pettigrew."
Silence.
"Pettigrew is dead," George said.
"Nobody saw him die. They found one finger." Draco met their eyes. "That's it. One finger, a crater in the road, and the testimony of a man who's been in Azkaban ever since."
Fred and George were both still now, in a way they very rarely were.
"If you're right," Fred said carefully, "Ron's been sleeping in the same dormitory as a Death Eater for two years."
"In the same dormitory as Harry Potter," Draco said. "Yes."
Another silence, longer this time.
"What do you want us to do?" George asked.
"Steal the rat. Make it look like a prank—nothing unusual from you two, nothing that would put him on alert if his instincts are still working. Don't let Ron know what you suspect; he'd argue for days and Pettigrew might bolt." Draco reached into his bag and set a small, sturdy container on the desk between them. "I've Charmed this. It'll hold an Animagus without being reversible from inside. Once you have it, bring it to me, and I'll take it to a professor."
"What if it's just a rat?" Fred said.
"Then Ron gets his rat back and we say nothing more about it." Draco shrugged. "No harm done."
George picked up the container and examined it. "And if it's not just a rat?"
"Then we'll have done something considerably more useful than most people manage in their second year at Hogwarts," Draco said.
The twins looked at each other again—the quick, private communication of two people who have been finishing each other's thoughts for thirteen years.
"Right," said Fred.
"We're in," said George.