The castle groaned in the cold night, stone settling like old bones shifting under centuries of magic.
Snape stood silently near the edge of a narrow, unused hallway in the third floor. The pipe system under Hogwarts stretched far and wide—older than most remembered, older even than some parts of the castle itself. But now it was louder. More active. Whispers, hissing, and the feeling of something slithering beneath the floors.
He cast a ward, then bent down to the wall.
"Sonorus."
The amplified whispering roared briefly—then a sharp hiss echoed so loudly it made him flinch. Not just whispering. Speech. Parseltongue. But what disturbed him most wasn't the words.
It was the pause. Like something on the other side of the wall… had sensed him.
He stood quickly and Disapparated, robes vanishing into the darkness in a swirl of magic.
---
Meanwhile – Gryffindor Common Room
Harry didn't sleep.
He hadn't for nights.
Every time he shut his eyes, he heard it—slithering through pipes, whispering from corners. Every time he turned a hallway, he expected someone else to be next.
Hermione dozed across from him in a chair, a book fallen on her chest. Ron snored somewhere upstairs.
And Harry just sat there, staring into the fireplace, holding the Marauder's Map in his lap.
Then—
A dot moved.
Harry blinked.
Draco Malfoy. Third floor. Near the Charms corridor.
At this hour?
He hesitated for half a second before grabbing his cloak.
---
Third Floor Corridor – Minutes Later
Draco stood by a curved stretch of pipe along the wall, brows knit. His wand was drawn, and he was muttering under his breath. He didn't hear Harry approach.
"What are you doing?"
Draco nearly jumped. "Merlin—Potter!"
Harry slipped out from beneath the cloak. "You shouldn't be here."
"You shouldn't either."
They stared at each other. Then, slowly, Draco sighed. "I keep hearing it. The voice. I followed it."
Harry stepped closer. "I did too."
There was silence for a moment.
Then Draco said, "It's getting louder."
Together, they pressed their palms to the wall.
Hiss. Whisper. Hiss.
Harry's heart pounded. He didn't know Parseltongue—but something about that sound felt closer. Too close.
And something cold brushed the back of his neck.
They turned at the same time—wands raised.
But there was nothing there.
Nothing they could see, anyway.
---
Snape's Private Lab – Later That Night
A cauldron hissed quietly in the corner as Snape scribbled a note beside a partially unrolled map of the castle's foundations. Runes from the Founders' era lined the margins.
He paused.
A section near the Charms corridor glowed faintly—only for a second—but he noticed.
He tapped the spot with his wand. "Track all magical disturbances within this section."
The glow deepened.
Snape's gaze narrowed. "So it's begun again."
A knock on his door interrupted his thoughts.
"Enter."
McGonagall stepped in, her lips pressed in a tight line. "Severus. Another attack."
Snape stood immediately. "Who?"
"A second-year. No one saw it happen. But she was found near the staircase to the dungeons."
He felt the chill settle into his bones.
"How long ago?"
"Half an hour."
Snape grabbed his cloak. "Show me."
---
Hospital Wing – Moments Later
The girl lay motionless, her expression frozen in fear, eyes wide open.
Madam Pomfrey hovered nearby, muttering diagnostic charms. Professors Flitwick and Sprout stood close, pale with worry.
Snape moved closer. He looked over the girl, then examined her hand.
Tightly clutched in her petrified fingers—
A single mirror shard.
"She saw it," he murmured. "Whatever it was."
McGonagall lowered her voice. "That's the third victim."
"And it won't be the last."
They exchanged grim looks.
---
Back in Gryffindor Tower
Harry returned to the dorm just before sunrise, his thoughts spinning.
Draco hadn't said much after they'd fled the corridor, but he'd looked shaken. Genuinely shaken.
Harry had never seen him like that.
Now, watching the sky lighten behind the frost-covered windows, he couldn't shake one last thought.
It's coming.
And somehow, it was looking for them.