Draco had intended to spend Christmas at Malfoy Manor.
Narcissa, however, had been in low spirits since her grandfather's death earlier that year, and Lucius had decided to take her skiing in Switzerland over the holidays. His letter to Draco on the subject had been brief:
Stay in the common room during the holiday and don't wander unless necessary.
Of 365 days in the year, Draco thought, they had to choose Christmas.
Then again, it suited him. He had research to do. Without Hermione's help, the Horcrux notebook — the one written partially in Ancient Greek — was slow going. He had been working through it in increments, and it was taking far longer than he would have liked.
Hermione Granger. He still wasn't sure what to do about her.
First she had trusted him, then she hadn't. Then she had been cold and distant, as if deliberately drawing a line between them; then she had blasted the rogue Bludger to pieces, as if she couldn't help herself. Then she had apparently been on her way to visit him in the hospital wing. Now she was avoiding him again, colder than before, for reasons he could only partly guess at.
He found the inconsistency both maddening and, if he was being honest with himself, somewhat difficult to walk away from.
The Christmas dinner was excellent. The Great Hall had been decorated lavishly — Christmas trees threaded with icicles or floating candles, the ceiling thick with enchanted snow that never quite fell. Draco ate a little and left early, saying goodnight to Crabbe and Goyle, who were still working through their third helpings, and to Blaise and Pansy, who were arguing with their usual focused energy.
He came back to the Slytherin common room to find Pansy rummaging through his Ancient Greek practice book on the carved table by the fire.
"What are you doing?" he asked.
The girl startled badly.
That was the first tell. The real Pansy Parkinson would never be startled by a question. She would simply look up, arch an eyebrow, and produce a withering remark. She certainly wouldn't flinch, go pink, and then explain in a perfectly reasonable voice that she was looking for her extracurricular reading.
"Is it your copy of Quidditch Through the Ages?" Draco asked pleasantly.
"Yes," said Fake Pansy. "That's the one."
Draco kept his expression entirely composed and let the silence run a moment longer than was comfortable.
The real Pansy was still in the Great Hall arguing with Blaise. Once those two started, it took at least an hour to reach a conclusion. And the person in front of him didn't know where the dormitory entrances were — she kept glancing in the wrong direction.
This was Polyjuice Potion, or he'd never seen it.
"I found it — it's in my room," he said. "Come on, I'll get it for you."
He led the way toward the dormitories with an air of complete unconcern, clocking everything: the uncertain hesitation behind him, the way she paused at the junction before copying his direction. Not from Slytherin, then, or at least not a regular visitor.
He opened the door to his room — single occupancy, the Malfoy name engraved in cursive on the antique panel — and stepped aside.
"Please come in," he said.
She peered around the doorframe with the expression of someone who has been curious about a room for quite some time and is now on the verge of satisfying that curiosity. She stepped over the threshold.
He closed the door.
She understood at once that something had gone wrong. Before she could move, he had her collar in one hand and his wand pressed firmly to the point of her nose.
"Who are you?" he said, very quietly.
"I don't — I don't know what you mean—"
"You walked past the girls' dormitory entrance. You didn't know it was there." He watched her face. "You're not from Slytherin. You've been going through my things. And Pansy Parkinson has never in her life been startled by a question." He kept his voice level. "I'll ask again. Who are you?"
She was pressed against the door, clearly frightened, which he noted and set aside — she had come into his house in disguise. He was not going to feel guilty about this.
"I didn't say anything," she managed.
"Then perhaps a spell will help."
"Let me go!" she said, and her voice had changed completely.
He released her immediately and stepped back.
Hermione Granger stood against his door, red-faced and gasping, pulling at her collar.
The Polyjuice Potion was already wearing off — he could see it happening, Pansy's features retreating like a tide pulling back.
Draco stared at her.
He became aware, after a moment, of several things he had done in the past thirty seconds that he would very much like to revisit.
"Hermione," he said, carefully. "What are you doing?"
"I could ask you the same thing!" she said furiously, still pulling at her collar. "I didn't know you could be like that!"
"You came into the Slytherin common room in disguise and went through my belongings," he said, with the precise calm of someone managing a strong reaction. "What exactly were you expecting?"
"I had everything planned perfectly!"
"You don't know where the dormitory entrances are."
"If you hadn't come back early—"
"Pansy will be back in twenty minutes," he said. "Probably with half the common room. If you walk out now, you'll have a very interesting conversation with our Head of House about how you got in here." He tilted his head slightly. "I'd suggest staying until the Potion finishes wearing off."
Hermione looked at him. Her jaw tightened. "I won't thank you for that."
"You're welcome," he said, and very deliberately moved to sit in the armchair by the window so she would have room.
A short silence.
"How did you know?" she said, with somewhat less heat.
"You were startled," he said. "Pansy is never startled."
Hermione's expression shifted — not quite a smile, but close. She looked down at her collar, straightening it.
"What were you looking for?" he asked.
She hesitated, then apparently decided that having been caught, she may as well be direct. "Your notebook. The one with the Dark Arts terminology — I thought it might have something about the Basilisk."
"You think I leave a book like that lying around in a common room?"
She had the grace to look slightly embarrassed.
"You could have come and asked me," he said, and heard his own irritation rise. "Instead you used Polyjuice Potion — how long did that take you to brew?"
"A month," she said, with a defiant lift of her chin.
"A month. Of a complex, restricted potion." He looked at her steadily. "Rather than walk up to me and ask me a question."
"You're impossible to ask! You're always — you never say anything directly, you're secretive about everything, and that parchment with the Dark Arts terms—" She stopped. Drew a breath. "The Chamber of Secrets opened not long after I translated that for you."
"So that's how you see me," he said. "A dark wizard scheming in the background."
"I didn't say that."
"You implied it."
"I was worried," she said, more quietly.
He looked away. The window was dark, the Black Lake pressing against the glass a few feet below — the common room sat well below the water line — and a large shape was moving in the shadows beyond the pane.
"I told Harry about the Basilisk theory to protect him," he said. "Not to manipulate him. Going after that voice unprepared could get him killed."
"How do you know so much about it?" she asked. "No one else — not even Professor Binns — could identify what kind of creature it was."
He chose his words carefully. "The evidence points toward a Basilisk. The nature of the attacks — petrification rather than death — suggests indirect exposure, something reflected or filtered. A Basilisk's gaze kills on direct contact but petrifies through an intermediary. Mrs. Norris was found near a puddle of water. Colin had his camera. Nick is a ghost, which presumably affected the outcome." He paused. "If you connect the cases, the pattern is consistent."
Hermione was quiet. He could see her working through it.
"And you told Harry about Parseltongue," she said slowly.
"He'd find out eventually. I'd rather he heard it in a way that let him prepare for the gossip." He glanced at her. "You'd worked it out already, hadn't you."
"I'd guessed," she admitted.
"Then we're both keeping things back from each other," he said. "That seems like something we might address."
Another pause. Longer.
"You had no idea Dobby was going to control the Bludger," she said. It wasn't quite a question.
"No," he said. "None. I was the one who broke thirty-four bones because of it."
She looked at the window. "I know. I heard you in the hospital wing."
"Then why—"
"Because I didn't know what else was going on that I didn't know about," she said. "You're very difficult to read."
"You should have asked."
"You should have said something instead of being so—" she started, and then stopped. She pressed her lips together. "We're going in circles."
He turned back to look at her properly, and she was watching him with an expression he found he couldn't quite categorise — not quite suspicious any more, but not entirely at ease either.
"Stop wandering around on your own," he said. "The Basilisk is real, and you're not in a safe position."
"Because I'm Muggle-born," she said, flatly. "Because the Basilisk targets—"
"Because you're more at risk than most students," he cut in, "for reasons that have nothing to do with your parents. Don't wander alone at night. Don't go exploring. Just—" He stopped.
He couldn't explain it. He couldn't tell her that he knew what was going to happen, that he knew exactly how this was going to go, that he was attempting to prevent it and was running out of time and methods and the Restorative Draught was still three weeks from being ready.
"Just be careful," he said.
Hermione was watching him with a strange expression.
"You're worried," she said slowly.
"I'm being practical."
"You said—" she started, and something shifted in her face. "Earlier. When I said you could just let me be petrified. You said—"
"I said nothing," he said, with some force.
"You said it would be too painful." She was smiling now, cautiously, like someone testing whether the ice will hold. "You said watching me turn to stone would be too painful."
He turned firmly to look out the window at the giant squid, which had drifted close enough to be visible — a vast, grey-shadowed bulk pressing one tentacle experimentally against the glass.
"I said nothing of the sort."
"I heard it very clearly." She sounded considerably more cheerful than she had any right to be. "Draco. Are you worried about me?"
"I'm going to cast a Silencing Charm on myself."
"You absolutely said it."
The giant squid scraped a tentacle along the window glass. The sound it produced was deeply unpleasant.
"That is revolting," Hermione said, momentarily diverted.
"It does this when something's in the room it finds interesting," Draco said, grateful for the interruption. "Usually it just lies against the common room roof."
"It finds us interesting?"
"Apparently."
They both looked at it for a moment. It pressed its tentacle against the glass again, producing a long, awful creak. Hermione winced.
"Stop arguing?" she said, not looking at him. Her voice had gone quieter.
"I wasn't aware I was still arguing."
"I mean—" She tucked a strand of hair behind her ear. "In general. There are clearly a lot of misunderstandings between us. I'd rather clear them up."
He considered this. "I'm not the Heir of Slytherin," he said. "I didn't open the Chamber of Secrets. I haven't arranged any of the attacks."
"I know," she said. "I didn't really think you had. I was scared, and I was making connections that weren't there." She paused. "I'm sorry."
He looked at her. She was staring at the squid with the expression of someone who is apologising and would prefer not to make direct eye contact while doing it.
"All right," he said. "We're even."
He tapped the round table with his wand, and a pot of tea appeared between them, steaming gently.
"Sit down," he said. "You'll need to wait for the party to wind down before you can leave anyway. Pansy will be back soon."
Hermione sat. She wrapped her hands around the cup and let the steam rise around her face, and the tension in her shoulders visibly decreased.
Outside in the common room, the noise was building — the after-dinner crowd returning in its usual green torrent. Draco crossed to the door, checked through the gap, and locked it. He cast a Muffliato and an anti-interruption charm, and the noise dropped away to silence.
"Milk?" he asked.
"Yes, please."
He poured it for her. The silver milk jug had the Malfoy crest engraved on the handle; he noticed her noticing it.
"How did you get the Polyjuice Potion?" he asked, sitting back.
"I brewed it." She caught his expression and raised her chin slightly. "It took a month. In Moaning Myrtle's bathroom. She was surprisingly accommodating."
"I believe it." He shook his head. "You could have asked me."
"Yes, well." She stirred her tea. "We've established that."
"Did you find what you needed, at least?"
"Not really. I still don't understand how the Basilisk moves without being detected." She frowned at her cup. "Given the size of the creature — the description in the texts is enormous — how does it travel through the school without being seen?"
Draco reached over and summoned a book from his desk with a wave of his wand. He set it on the table between them.
"Chapter fourteen," he said. "It has the most thorough account I've found."
She opened it immediately, and he watched her read with the efficient, devouring speed she brought to anything she considered useful. Within a few minutes her expression had shifted from concentration to something approaching illumination.
"I see," she said, mostly to herself. "So the castle has — and the pipes would still run through the original structure even after—" She stopped. She looked up. "Draco. The pipes."
"What about them?"
"That's how it moves." She set the book down, her eyes bright. "The castle is full of pipes — they predate most of the renovations, they run through every floor and wing. A Basilisk moving through the pipes would be invisible. It could be anywhere." She sat back. "That's why no one's ever seen it travelling. It doesn't travel through the corridors at all."
Draco stared at her.
That was the answer. He had known the answer for months — had been sitting with it, knowing it from his previous life — and she had arrived at it from first principles in ten minutes.
"Yes," he said. "That's exactly right."
She was smiling, the pleased-but-controlled expression of someone who has solved a problem and is trying not to be too obviously satisfied about it.
"You knew," she said.
"I suspected," he said. "You proved it."
"We proved it," she corrected.
He refilled her cup without being asked. The giant squid drifted away from the window, apparently satisfied, and the common room noises beyond the door settled into the lower hum of late evening.
"So," Hermione said, curling her fingers around the warm cup. "What do we do with this?"
"Think," Draco said. "Carefully. Before doing anything else." He looked at her across the steam. "A Basilisk that travels through the pipes can emerge from any drain or fixture in the castle. The Chamber of Secrets is the point of origin, but we don't know where the entrance is. Until we do, we can't end this."
"Then we find the entrance," Hermione said.
"Then we find the entrance," he agreed.
Outside, the Black Lake pressed dark and deep against the window. Somewhere far above them, the rest of the school was celebrating Christmas.
In the Slytherin dormitory, they drank their tea and started to think.