It began, as many bad ideas at Hogwarts did, with curiosity.
Late at night, Harry had crept out under the Invisibility Cloak. He wasn't alone. Ron and Hermione followed close behind, whispering nervously as they turned the corner past the trophy room.
Draco, who had tailed them from the common room out of equal parts suspicion and something else entirely, had no intention of staying behind.
"I told you we shouldn't be out," Hermione hissed. "If we get caught—"
"We won't," Harry said, tugging the cloak tighter. "I just want to check if the corridor's still guarded."
"You're going back to the third-floor corridor? Are you mad?" Ron snapped.
Harry didn't answer. The pull toward that place—where Fluffy had guarded something mysterious—had been gnawing at him for days.
When they arrived, the door was ajar.
And that's when it all went wrong.
A loud creak of wood echoed down the corridor as the door inched further open—and at that exact moment, Filch turned the corner behind them, lantern held high.
"Well, well, what do we have here?" he snarled.
The students froze.
Then—
"RUN!"
They scattered. Harry darted one way, Hermione another. Ron tripped over his robes, and Draco stood frozen until Filch grabbed the back of his collar.
By morning, they were all seated outside McGonagall's office, side by side like mismatched chess pieces. Draco scowled at the floor. Hermione kept trying to explain. Ron looked half-ready to vomit, and Harry said nothing.
Snape appeared before McGonagall could speak.
"I'll deal with them," he said coldly, black eyes glittering.
McGonagall narrowed her eyes. "All four?"
"Yes," he said, with quiet certainty. "They broke curfew. They entered a forbidden corridor. And I suspect they've grown far too comfortable taking liberties."
Hermione opened her mouth, but Snape raised a hand.
"Save it."
He turned on his heel. "Follow me."
---
They followed in tense silence, all the way down to the dungeons, where Snape's robe swept past stone walls like a living shadow.
He stopped abruptly in a small, torch-lit hallway.
"You will serve detention in the Forbidden Forest tonight," he said. "There's been unusual activity there. Something dangerous."
Ron turned pale. "Wait—like... dangerous how?"
"That is not your concern."
"But—sir," Hermione began. "Isn't that... unsafe?"
Snape's mouth twitched. "Perhaps you should have considered that before wandering into locked corridors after hours."
"But why all four of us?" Draco muttered. "It was Potter's idea."
Snape turned on him. "You followed him. And I expected better of you."
That silenced Draco more effectively than any threat.
"Report to Hagrid's hut at sundown," Snape finished, sweeping away.
But as he walked, his eyes flicked briefly toward Harry's—something unreadable passing between them.
A warning. A promise.
---
That Night – The Forbidden Forest
The forest was colder than Harry remembered. Mist clung to the ground, swirling around their feet like ghostly fog. The sky above was black and cloudless, and Hagrid's lantern cast golden halos in the gloom.
"Stay close," Hagrid warned. "Unicorn's been hurt. Something dark's lurkin' in these woods."
Hermione shivered. Ron looked ready to bolt. Even Draco, whose sarcasm had returned full force earlier, was now completely silent.
They split into two groups.
Hagrid with Ron and Hermione.
Fang with Harry and Draco.
"Great," Draco muttered. "Alone in the woods with you and a slobbering dog."
"Don't worry," Harry said flatly. "You'll be too scared to talk anyway."
They pressed deeper into the woods. Branches clawed at their robes. Somewhere above, wings fluttered. Then—something glimmered ahead.
A pool of silver blood.
Draco stepped back. "Unicorn blood."
"Yeah," Harry said quietly. "Something's hunting."
Then they saw it.
A shadow gliding between trees. Not walking—floating.
It moved toward the body of a fallen unicorn, lowering its hooded head. As it began to feed, the blood glowed faintly in the moonlight.
Fang whimpered and ran.
Harry stood frozen, until pain lanced through his scar, sudden and searing.
He dropped to his knees, gasping.
The creature turned.
It saw him.
Then it began to move toward them—too fast, too silent.
Draco grabbed Harry's arm. "Move!"
They ran, crashing through trees and underbrush. The shadow followed, gliding like mist, gaining on them.
Harry stumbled.
The pain in his head exploded.
The shadow lunged forward—
And was blasted backward in a flare of green light.
Snape emerged from the trees, wand drawn, eyes fierce.
He stood between Harry and the shadow, robes whipping in the wind. "Stay back," he snarled, voice deadly calm.
The creature hissed, then vanished into the mist.
Silence fell.
Harry lay gasping. Draco crouched beside him, pale and shaking.
Snape knelt beside them, wand still raised. "Are you injured?"
Harry shook his head weakly. "My scar—it burned—"
"I know," Snape said softly.
He glanced toward the place where the shadow vanished, then back at Draco.
"You both should be dead," he said coldly. "And if you ever enter this forest again without a professor, you just might be."
But his hand briefly touched Harry's shoulder—just long enough for comfort.
Just long enough to say: You're safe now.