There was a cerberus in the school, and Leo had never run faster in her life. She was sure Mrs. Norris had started yowling at one point, and the added danger of Filch only made her try to speed up.
A cerberus, she recited in her mind, thinking back on all the creature study she'd done, is a very rare magical beast with three heads. She knew that, of course. She'd just seen it with her own two eyes. The cerberus boasts a size and strength that largely dwarfs that of non-magical dogs.
Regulus was growling at her to find a place to hide. That running through the halls might just catch more attention. She opened a door, cast a look about the empty room, then threw herself inside.
Panting and pressed up against the stone wall with her eyes shut tightly, she thought, Each of a runespoor's heads have a different function. It's unknown if a cerberus works similarly. And then, Sometimes, the two left heads will bite off and consume the rightmost head. It's not uncommon to find runespoors that have eaten parts of themselves in such a manner.
She opened her eyes. This classroom was clearly unused. Desks were pushed against walls, chairs stacked atop them. And there was a mirror.
The mirror didn't make sense for an abandoned classroom.
She didn't move from her spot, studying every curve to the mirror's golden frame. It was much larger than a mirror had any business being. The angle was wrong for her to see herself in it, but she wasn't sure yet that it was safe to move. There were markings along the top, something engraved that didn't match the rest of the filigree. She stepped towards it, eyes trained upwards on the etching.
ERISED STRA EHRU OYT UBE CAFRU OYT ON WOHSI.
She was distracted by Regulus moving at the bottom edge of her vision. He was smiling, and why would he be—
When she looked down, she came face-to-face with her own reflection, Regulus's hand solid on her shoulder. She sucked in a breath and snapped her gaze to her own shoulder, not her reflection's. Regulus's hand wasn't there. Of course it wasn't. He couldn't touch anything, and no one could touch her. That was how it had always been.
She found the real Regulus floating halfway through the door to the classroom, looking out for Filch.
She turned back to the mirror. The Regulus there still had a hand on her, and he had more color than she'd ever seen him outside her—his—memories. There was none of the blue desaturation of death on him. And there were people around him. No, people around her.
Regulus was standing right behind Draco, who was holding her left hand. Lucius and Narcissa, arms linking them together, were standing behind her other shoulder. And Percy was there, too, off to her right and smiling as he looked over a scroll in his hands.
As she stared at her reflection—her, it was definitely her, there was nothing different with her or Draco or anyone else the way there was something different with Regulus—Narcissa smiled and leaned down. Her slender fingers curled under Leo's chin, and she pressed a kiss to her temple. Lucius lifted a hand to Leo's ribbon. Not a ribbon wound between her hand and his but the ribbon laced through her messy attempt at a crown braid. It had taken her long enough that morning that Daphne had set her box of hairpins in front of her on the bathroom counter before she'd left for the Great Hall. The braid had spent most of the day hidden under her hat until she'd removed it half-way through practice with Percy.
In the mirror, Percy looked up from the scroll, grinning, and reached out to clap Leo on the shoulder, clearly pleased with whatever he'd been reading. Draco yanked on her hand until her reflection looked at him. The Regulus in the mirror was looking down at her with some kind of expression she'd never seen on him before. He was smiling, still, and there was something bright in his eyes.
"Merlin?" she asked.
"What?" Regulus asked from the door, finally pulling himself all the way into the room. "I don't see Filch. What is it?"
"Do you see them?"
"See what?" he asked, moving to her side, standing behind her.
She lifted a hand to point in the mirror. Her reflection didn't copy her, instead tilting her head back to beam up at her parents, baring her teeth and her throat all in one. "There are people in the mirror with me. You're in the mirror with me. Do you see it?"
He didn't answer.
She leaned her head back to frown up at him. "Mer?"
He was staring at the mirror with wide eyes. "It's done," he murmured.
"What's done?"
"The locket. It's destroyed."
She snapped her gaze back to the mirror. The Regulus there was squeezing her shoulder. Draco was still pulling on her hand, laughing. Percy was holding something out for her reflection to read. And Narcissa and Lucius kept their hands on her—on her cheek, on her hair, on her neck, on her. The locket wasn't anywhere there. She knew it was still hidden under the floor beneath her bed at the Manor where she'd kept it since she was nine.
"I don't see it," she murmured. "Why can't you see them?"
"It's just the locket. You're not even there." Regulus moved closer to the mirror, less than an inch now from the surface. "What type of magic is this mirror?"
"I don't understand the inscription," she said, pointing. Regulus floated upward to look at it, but she kept staring at the image being shown to her.
She wasn't sure how long it had been, but finally she looked up at Regulus. He was still studying the words, if they could be called that.
ERISED STRA EHRU OYT UBE CAFRU OYT ON WOHSI.
Leo reached up. Her hand was trembling a bit, and she couldn't understand why. She'd long since mastered Wingardium Leviosa. There was no reason for her to be shaking. But there was a tremor in her fingers as she reached for Regulus's ankle. Her hand went through him, and she choked on a breath. The room swayed a bit. She lowered her hand, reaching for the floor and using it to steady herself as she sank down.
She stared into the mirror again, pulling her knees up and hugging them. The Percy in the mirror was frowning at her—her, not her reflection—and she recognized the look as similar to the one Draco had been giving her for a week now. The Regulus in the mirror was still looking down at her reflection, still smiling. She finally recognized that look. He was proud.
Her eyes had started to hurt, and it was quite a while after Percy had returned to showing her reflection a book that she touched her fingers to her face. She was cold, but she was always cold, so that didn't explain why she was shivering. She was used to the cold. But nevertheless, the fingers that touched her cheek quivered and came away wet.
"Oh," she mumbled. "Mer, I'm crying."
Regulus looked down at her with a frown, finally turned away from the inscription. "Why?"
"I don't know," she whispered. "I thought you could tell me."
"I can't." He floated down and crouched so that he was level with her. His brow was furrowed and his lips turned down. "You have to figure it out. That's how that works. It's all in your head."
"People would say that you're all in my head. If they knew."
"They don't," he said firmly. "They don't know. And I can't help you."