There was a troll in the dungeons.

"How?" Leo asked while the other students were scrambling up to follow their prefects.

"Who," Regulus corrected. "A troll can't get in on its own."

She eyed the Defence Against the Dark Arts professor that Hagrid was helping to his feet. "Charmingly good wizard, isn't he?" she drawled.

"Prefects," he reminded her.

"Nag." She gave an upset sniff as she finally stood and gathered her bag. "I haven't had dessert yet," she mourned. But nevertheless, she followed after everyone else, the majority of the professors having already left as well. She could see the end of the crowd of Slytherins headed towards the stairs with the Hufflepuffs instead of either House going to the dungeons.

It was Regulus that started snarling at her until she ducked into an alcove at his bidding. "What?" she whispered. "I'm not a fool. I don't want to wander when a troll—"

"Snape isn't going to the dungeons with the other professors," he interrupted.

"And?" she hissed. But her heart was already sinking into her stomach, pulse quickening. She knew exactly what he wanted. "No."

"He's a—"

"I know what he is," she said, voice shaking. "But there's a— It, it's not like the tree. I knew what was happening with the tree, didn't I? But a troll—"

"Find out what the Death Eater is doing."

It was a demand. Leo curled in on herself, heart still rattling about her ribs. "Which way?" she whispered. She palmed her wand.

Regulus was jittery and angry alike as he guided her after Snape, floating ahead as far as he could and then snapping back to her side with directions. Her own nerves were alight, and she kept glancing about as she moved through the halls. She wouldn't put it past Regulus to be so fixated on Snape that he would forget about the—

She yanked herself behind a suit or armor, pressing herself against the wall. Regulus's warning had come just in time, because it was only a couple seconds later when a figure rushed past. Someone was talking. Whispering. Hissing. She caught a blur of purple.

"You've failed."

"I'm sorry, Master. I never intended—"

As he disappeared around the corner, the voices still lingering in Leo's ears, she realized that she knew who it was. "Quirrell?" she asked, voice quiet. "That didn't sound like Quirrell."

Regulus was chattering. Shaking.

"Mer?" she breathed. "Mer, please. Don't—" She glanced about the hallway. No Snape. No Quirrell. No troll. No guarantee it would be like that for long.

Gripping her wand tightly and glancing frantically between the ghost spiraling beside her—he was moaning, now, clutching his arm—and the rest of the corridor, she took off the way she'd come. The troll was in the dungeons. Where would the Slytherins have gone instead? What was up the stairs? Everything was up the stairs. She hurriedly retraced the way she'd come, lip stinging and wand trembling and—

"Malfoy, what are you doing?"

She snapped around. Regulus was still lost to her. Despite that, the moment she saw Snape, she focused on occluding. Shielding."Professor Snape," she said, not having to fake the anxiety in her voice but leaning into the panic for her story. "I don't know where my House went. I left the Great Hall later than everyone else. And with the troll in the dungeons, then surely it wouldn't be wise for—"

"You shouldn't be wandering about," Snape said sharply. He frowned down at her for a moment and—

Someone was shouting. Screaming.

"With me," he snapped, limping past her towards the noise.

Limping?

She turned to stare at him.

"Malfoy!"

She hurried after him.

The yelling had stopped, but she heard a slam just before she followed Snape around a corner and saw McGonagall and Quirrell standing in the entrance to the girl's lavatory. Quirrell gave a shuddering sound, hand going to his chest as he sank to the floor. Snape flicked a hand towards her to tell her to stay put and then strode forward.

"What on earth were you thinking?" McGonagall demanded.

Leo kept only half an ear on the conversation, staring at Quirrell. His shoulders were quivering, and she couldn't understand why he'd been in the third floor corridor. Who he'd been speaking to. Why Regulus was still not quite there.

When the three Gryffindors shuffled out of the room, she looked up at them. Their eyes widened. Before they could say anything, though, McGonagall had stepped up behind them. "Miss Malfoy," she said sharply. "Why aren't you with your House?"

She blinked. It was then that she realized she'd never put her wand away. She forced her hand to relax, nails lifting from where they'd dug into her palm. "I got separated. I don't know where they went."

McGonagall huffed and glanced at Snape. After a moment, she nodded. "Very well. To your dormitory as well."

"Of course, Professor. Thank you." She glanced at the three Gryffindors, and Ron and Harry were frowning at her. She wondered how the three of them had possibly dealt with the trolls themselves. She finally put her wand away in her robes and left for the dungeons.

Leo stood in the middle of the empty Slytherin Common Room, staring at Regulus as he sobbed. "This is unhelpful," she finally said.

He gave a shudder, hands pressed over his ears.

"Talk to me about Quirrell, at least," she insisted. "Help me. Something's wrong with him."

Regulus's gaze flicked up towards her, but he definitely wasn't seeing her. Leo hunched her shoulders and ducked her head. She wouldn't beg. It wouldn't help.

The Common Room door opened with the sound of stone against stone. As the other Slytherins began to pour inside, speculating loudly about the feast and the troll and their homework, Leo drew her arms in close. Glancing about at her fellow students, she moved for one of the windows to limit how close people could get to her. She sank down onto the bench and lifted a hand, thumbing over her stinging lip. It came away with a touch of blood. She must have been chewing again.

"You came here?" a horrified voice asked.

She looked up to find Draco just then coming to a stop by the window. His eyes were wide, his face paler than normal. He raked his gaze over her before lingering on her face. He started fumbling for his pockets. "You're bleeding," he mumbled. "Did you—"

"I got separated from the House, and I didn't know where it went. Professor Snape found me and sent me here after the troll was dealt with," she reassured him.

He nodded, swallowing visibly, and finally came up with a handkerchief. He held it out and then dropped it into her waiting palm. She focused on dabbing at her lip instead of listening to Regulus's wailing. She wished he would stop. Her head was aching, and she could feel it growing worse the longer and louder he went on.

"—listening to me?"

She blinked down at the handkerchief. It was spotted, now, and she could remember the way Dobby always tutted when he was spelling the blood out of her clothes. He didn't have to do it much—mostly only after her worse nightmares—but when he did, he always looked her over with a frown and a sad shake of his head.

"Hey!" Draco snapped his fingers in front of her. "Look at me."

She did so and found that he looked awful. "Are you sick?"

"No." The word came at her sharply, and the question seemed to have upset him. "You're an idiot."

"I didn't realize I was a mirror," she mused, looking down to consider the handkerchief again. "Are you wanting this back?"

Draco huffed. "Did you see the troll?"

"Hmm? Oh, yes."

He made an odd sound. Then he told her to keep it, turned on his heel, and left.

That night, Leo dreamed of her home's drawing room from before she was born. Before she learned to stop being afraid of it. Before she sat at her mother's feet with her brother, listening as Narcissa spoke with Lucius over tea. Before she started sitting at the piano and running cold fingers over cold keys.

That night, Leo dreamed of a man that wasn't quite a man. His voice was cold and familiar and she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd heard it, she'd—

The night, Leo woke up not long after falling asleep and decided she didn't want to dream anymore.