Lydia Marwood had always believed Hogwarts held more secrets than even Dumbledore let on, but nothing had prepared her for this.
The door loomed before her, half-hidden in the shadows of the musty, abandoned corridor. It was unlike any other door in the castle—made of dark wood that seemed to hum under her fingertips, etched with swirling runes that pulsed faintly in the dim torchlight. Marcus Avery stood beside her, his breath shallow with anticipation.
"I don't like this," Marcus muttered. "Doors that appear out of nowhere? That's never a good sign."
Lydia rolled her eyes. "Would you rather we ignore it and pretend we never saw it?"
"Yes, actually. That would be smart."
But Lydia wasn't one for ignoring mysteries. That was why she had followed the strange, flickering light the night before, why she had traced the whispers that called her name in the wind. It had all led her here—to this hidden door.
She took a deep breath and reached for the handle.
The moment her fingers brushed the metal, the runes flared, glowing blue, then gold, then white-hot. A pulse of energy rushed through her, like a heartbeat pounding against her palm. The air crackled. She heard Marcus swear under his breath as the door swung open with a groan.
Beyond it, there was no ordinary room. No stone walls, no enchanted torches—just a swirling void of mist and shadow, stretching endlessly into the dark. The ground beneath their feet looked solid, but the space ahead of them twisted and shifted, like a reflection on rippling water.
"This is bad," Marcus whispered.
Lydia, however, took a cautious step forward. "This is incredible."
The moment she moved, something in the mist stirred. Shapes flickered—half-seen figures, echoes of things not quite real. She caught glimpses of landscapes, towering spires of black stone, glowing rivers, an entire city that shimmered and vanished like a mirage.
Marcus grabbed her wrist. "Lydia, I'm serious. This isn't Hogwarts anymore. We need to leave."
But before she could answer, a sound echoed through the space—a low, resonant hum. It vibrated in her bones, tugging at something deep inside her. Then, out of the mist, a figure emerged.
It was cloaked in darkness, its form shifting like smoke. Eyes burned from beneath the hood—a molten gold, ancient and knowing. When it spoke, its voice was like a whisper carried on the wind.
"You have found the Threshold."
Lydia swallowed hard. "Who are you?"
"A guardian," the figure said. "A keeper of paths. And you, child of magic, have stepped where few dare."
Marcus tightened his grip on her wrist. "Right. That's our cue to leave."
But Lydia was rooted to the spot. "What is this place? What do you mean, 'threshold'?"
The figure tilted its head. "There are many worlds, many realms, hidden beneath the surface of what you know. Some are mirrors of your own, others... vastly different. This door does not simply open—it chooses. And it has chosen you."
Lydia felt a chill run down her spine. The idea of multiple worlds wasn't new to her—Hogwarts, after all, was filled with doors that led to unexpected places. But this was different. This was something bigger.
"Why me?" she asked. "Why now?"
The figure lifted an ethereal hand and pointed. Behind Lydia, on the stone wall of the castle, the runes had rearranged themselves into a single, glowing word: Marwood.
Her surname.
Marcus sucked in a breath. "Okay. That's not creepy at all."
Lydia stared, heart hammering. "I don't understand. What does my family have to do with this?"
"That is for you to uncover," the guardian said. "But know this—once you step through, the path will not be so easily closed. Choose wisely."
The mist swirled again, and the guardian's form began to dissolve, its golden eyes the last to fade. The hum in the air lessened, the shadows retreating slightly.
Lydia turned to Marcus. "I have to go."
His eyes widened. "Lydia, no! Are you insane?"
"This door appeared for a reason. My name is on that wall. Whatever this is, it's tied to me."
Marcus ran a hand through his hair. "And that's exactly why you shouldn't just jump into the unknown! What if you can't come back? What if this is some kind of trap?"
Lydia hesitated, but deep inside, she knew—this was something she couldn't walk away from. Something was calling her, pulling at the edges of her soul. She had spent years chasing answers about the hidden depths of magic, and now, for the first time, it felt like the magic was reaching back.
She squared her shoulders. "I have to do this."
Marcus groaned. "Fine. But I'm coming with you."
Lydia gave him a small smile. "I was hoping you'd say that."
Together, they stepped forward. The mist curled around them, the world shifting. And then, in a blink, they were gone.