Chapter Text
The post-war world felt different at Hogwarts. The castle itself stood tall and resilient, though still scarred from the final battle. The rubble was mostly cleared, the hallways no longer filled with whispers of terror. Yet, for Harry Potter, there was a lingering emptiness he couldn’t shake. Perhaps it was the ghosts of what had been lost, or perhaps it was the strange sense of detachment from his purpose now that the prophecy had been fulfilled.
As he wandered through the castle halls late at night, hands buried deep in his pockets, the weight of peace seemed heavier than the war itself. The silence was thick, only broken by the occasional crackle of a torch or the distant sound of Peeves causing trouble. Harry found solace in these walks, away from the prying eyes of curious students and the concerned glances of his friends.
His footsteps echoed along the stone floors as he made his way to the Astronomy Tower, his favorite place to think. It wasn’t far from where he’d once stood with Dumbledore, but now, instead of looming danger, there was only a vast, dark sky littered with stars.
The night was cool, crisp air filling his lungs as he leaned on the edge of the tower’s railing. Below, the Black Lake shimmered under the pale moonlight, its surface unnervingly still. Hogwarts was sleeping, safe and sound, and Harry should have felt content. He had saved everyone, hadn’t he?
But the nagging emptiness persisted.
Harry sighed deeply, tilting his head back to gaze at the stars. It was in moments like this—quiet, reflective moments—that he felt closest to his parents. He often wondered what his life would have been like if they were still alive. He imagined James sitting beside him, teasing him about his messy hair, and Lily offering him comforting words whenever his mind raced too fast.
The thought of James brought a memory from deep within, one that had always been just out of reach but now resurfaced more clearly. A soft whistle, melodic and warm, from the days when he was too young to understand the world around him. James used to whistle a tune—just a simple song—before bed, lulling Harry to sleep on those rare peaceful nights in Godric’s Hollow.
The memory was so faint, but it tugged at something deep in Harry’s chest, something vulnerable and fragile.
Almost unconsciously, Harry started to whistle the tune. The notes were light, hanging in the night air like wisps of a forgotten dream. It was soft, almost hesitant, as if he feared the melody might break apart if he whistled too loudly. The tune was simple, a few notes rising and falling, like waves crashing gently on a distant shore.
As he finished the last note, silence returned. Harry closed his eyes, letting the quiet night wash over him. But just as he was about to turn away and head back inside, something stopped him cold.
Another whistle, faint but unmistakable, echoed back to him.
Harry froze, his heart skipping a beat. For a moment, he thought he’d imagined it. He leaned forward, eyes scanning the grounds, trying to find the source of the sound. But there was no one. The grounds were as empty as they had been all night, and no movement disturbed the calm surface of the lake.
But he had heard it. He was sure of it. The same tune, the same melody, as though someone had been listening—waiting—and whistled back to him.
“Hello?” he called out, his voice low but urgent.
No answer came, only the quiet hum of the night. Harry waited, his senses on high alert, but after a few minutes, he shook his head, telling himself it had been a trick of the wind. Still, a small sliver of doubt nestled in his mind.
Reluctantly, he made his way back to Gryffindor Tower, his mind replaying the strange event over and over. By the time he climbed into bed, sleep was elusive, the echo of that whistle lingering long into the night.
---
The next morning, Harry barely touched his breakfast. He picked at his toast, his mind far from the conversations buzzing around him in the Great Hall. Across the table, Hermione and Ron were deep in discussion about their upcoming assignments, while Neville was recounting some of the greenhouse experiments he’d been working on with Professor Sprout.
“Harry?” Hermione’s voice broke through his thoughts.
“Hm?” he mumbled, blinking as he realized both Hermione and Ron were looking at him with concern.
“Are you all right?” she asked, her brow furrowing. “You look like you didn’t sleep at all.”
“I’m fine,” Harry lied, pushing his food around his plate. “Just… thinking.”
“Thinking about what?” Ron asked through a mouthful of eggs. “You’ve been all quiet since last night.”
Harry hesitated. He hadn’t told anyone about the whistling, partly because he wasn’t sure what to make of it himself. It had probably been nothing. But the gnawing feeling in his gut wouldn’t go away.
“It’s nothing,” Harry said finally, though Hermione gave him a knowing look. “I just—”
Before he could finish, a sharp whistle cut through the air.
Harry’s head snapped up, and his heart lurched in his chest. The same tune—the exact same tune—was being whistled from somewhere else in the hall. He scanned the room quickly, his eyes darting between the faces of the students seated at their tables, but no one seemed out of place.
Ron raised an eyebrow. “What’s gotten into you, mate?”
“Did you hear that?” Harry asked, his voice tight.
“Hear what?” Ron looked around, confused.
“That whistle. Someone just whistled.” Harry’s pulse quickened, but Ron and Hermione exchanged confused glances.
“I didn’t hear anything,” Hermione said, looking slightly concerned.
But Harry knew he wasn’t imagining it. That tune—it wasn’t a coincidence. Someone else knew it, and they were communicating with him. He pushed back his chair and stood up abruptly.
“I’ll be back,” he muttered, ignoring their protests as he left the Great Hall. His heart raced as he hurried down the corridor, looking for any sign of the person who had whistled. But the hallway was empty, and the sound had vanished, leaving Harry with only more questions.
---
Draco Malfoy sat at the far end of the Slytherin table, his face carefully composed as he buttered a slice of toast. But beneath the surface, his mind was racing.
He had recognized the tune the moment he heard it. It was a song from his childhood, a melody that had been hummed to him by none other than Regulus Black. The older cousin had visited the Manor from time to time when Draco was very young, often sneaking into his nursery to soothe him to sleep. Regulus had always been different from the other Blacks—softer, gentler. Draco had adored him, even if those memories were hazy now.
But that song, that whistle—it had stuck with him. He hadn’t heard it in years, and certainly never outside the walls of Malfoy Manor.
So who, in the middle of the Great Hall, knew it?
Draco glanced around cautiously, his gaze flickering across the tables. Potter had been the one to react most strongly to the whistle, leaving abruptly after hearing it. Could it have been him? The idea seemed ridiculous—what connection could Potter possibly have to Regulus?
Draco sighed, pushing his plate away. He couldn’t shake the eerie feeling that someone, somehow, was reaching out to him through the familiar melody. But why? And for what purpose?
The questions nagged at him, but for now, he would have to wait for answers.
---
That night, Harry found himself back in the Astronomy Tower, his heart still unsettled from the day’s events. He stood in the same spot as before, gazing out over the grounds, the same tune swirling in his mind.
Hesitantly, he began to whistle again.
The notes floated into the night, soft and searching. For a moment, there was only silence, and Harry felt the sharp sting of disappointment.
But then, faintly—just barely audible—a whistle echoed back.
Harry’s breath caught in his throat. It was real. Someone was there, someone knew the song, and they were answering him.
Who are you? Harry’s mind raced, but he had no way of asking, no way of knowing.
He would have to find out.