A transfer student arrives at Hogwarts without warning.
Her name is Aurelia. Long black hair, gray eyes with no warmth in them, and an aura that feels just a little wrong. The shadows around her move on their own. The air near her drops a few degrees. Students and teachers alike feel their bodies stiffen when she walks by.
One person noticed her from the very first moment—Potions Master Severus Snape. Known for his cold stare and cutting words, he begins observing Aurelia in secret, asking him
Obscurus - Smiling Poison—Lynnea's Trap Shatters the Classroom
That night still lingered in her mind.
The collection in the herb garden, the moment her fingertips came within a centimeter, and how the air had grown cold. Since then, Aurelia had consciously kept a lid on her emotions. She clamped it down, locked it, and piled heavy things on top. It had become her daily routine.
By mid-October, the underground sections of Hogwarts grew genuinely cold from the ground up. Even wearing Slytherin robes, the soles of her feet felt a chill against the stone floor. Because the dormitory sat at the bottom of the lake, the temperature was always about two degrees lower than outside.
That morning too, the Great Hall was full of energy.
The ceiling reflected thick clouds. Students sat at four long tables, chatting as they ate breakfast. The smell of scrambled eggs drifted through the air, and a raven cawed outside the window—apparently someone had dropped their toast.
Aurelia walked toward the Slytherin table. She checked for empty seats. There was one at the end, near the window.
She tried to sit down and stopped.
A leather bag sat in that seat.
The student in the next chair—a third-year girl with brown hair—seemed to feel her gaze and looked over. Their eyes met for a moment. Then she immediately looked away. No words, no explanation. She simply looked away.
Aurelia searched for another seat. There was an empty one a bit further down. She walked toward it, and again there was a bag.
Once more. Another bag.
Aurelia quietly surveyed her surroundings. No one would meet her eyes.
(I see.)
That was all she thought. She didn't let her emotions move. Standing at the edge, she slowly processed the situation.
That was when it happened.
"Oh, Aurelia! Come over here!"
A bright voice called out. She turned to see a girl waving from the middle of the table. She had vivid purple long hair loosely curled, bright golden eyes, and a dazzling smile. There was a small beauty mark at the corner of her lips.
It was Lynnea Vaara. A sixth-year Slytherin. The girl who had smiled at her several times in the corridors since she'd transferred.
Aurelia approached. There was indeed an empty seat next to Lynnea.
"[excited]You were looking for a seat, weren't you? This one's open, so sit here"
"[gentle]...Thank you very much"
As she sat, she glanced sideways at Lynnea.
She was smiling. A perfect smile. But there was nothing behind her eyes. Her pupils weren't smiling. There was a quiet light in their depths—the kind that assessed, that calculated.
(This person is dangerous.)
That was how Aurelia categorized her.
She harbored an Obscurus. She was used to people avoiding her because of it. But the kind of danger that approached with a smile was a different matter entirely. She should be carrying something far more troublesome than this person, yet somehow this smile was genuinely frightening—she almost laughed at the thought.
"[excited]The Potions lessons lately have been amazing, haven't they? Professor Snape said your work was precise"
"[gentle]...Is that so?"
"[sarcastic]Durmstrang really does have high-level instruction, doesn't it? That's impressive"
The way she said "impressive" was too clean, too perfect.
Aurelia simply offered a brief thanks and lowered her gaze to her toast.
---
That afternoon, she went to the library.
She wanted reference materials for the next day's Potions practical. She needed theoretical backing for the interaction between moonwort and gentian.
When she asked Madam Pince for "Volume Four of Advanced Potion Preparation from the third shelf," the librarian checked the lending ledger.
"It's checked out."
"Then Volume Three?"
"That too."
"Volume Two?"
"...They're all out."
Aurelia asked if she could see the lending ledger. Madam Pince opened the book. Aurelia's eyes fell on the most recent entry.
—Lynnea Vaara.
She had checked them all out this morning.
"I understand," she said simply, and left the library. She didn't let her emotions move.
---
That night, in the Slytherin common room.
The green light from the lake bottom wavered across the walls. Several older students sat on leather sofas, deep in conversation. Aurelia was at a table in the back, reviewing her notes for the next day's practical.
Voices drifted over. She hadn't meant to listen. But in a stone room, voices echoed.
"She got kicked out of Durmstrang, didn't she?"
"Really? Why?"
"I heard there was an accident during a practical. Something weird with her magic."
"She's been sucking up to Professor Snape, apparently. It's creepy."
"Right? Like, when she's nearby, the air feels weird."
Aurelia didn't look up from her notes.
Lynnea was at the center of the group. With a worried expression, she was saying, "It's scary, but I don't want to be mean to her either..." Her face was that of a concerned friend looking out for her companions—anyone would have believed it.
Aurelia quietly closed her notebook and headed to the dormitory.
---
Potions the next morning was at nine o'clock.
As she descended the stone steps, the distinctive smell of potions hit her nose. The scent of damp stone mixed with something sour and bluish. The classroom was at least two degrees colder than the corridor. Yellow torchlight illuminated shelves lined with bottled specimens.
Today's practical was an advanced moonwort preparation. Each student's cauldron was already set up.
Snape confirmed the procedure from the lectern.
"[serious]Add the stabilizing agent to the moonwort extract. The timing is critical—within thirty seconds of the liquid becoming transparent. Any later and the components will decompose"
The practical began.
Aurelia arranged her tools and checked the heat. The moonwort extract had already been prepared yesterday. The timing for adding the stabilizer had to be precise.
In the bustle of activity, Aurelia didn't notice.
The moment Lynnea passed through the adjacent aisle.
She held a small glass vial in her right hand. A vial no bigger than a fingernail. As she passed, for just an instant, she extended her hand—
A few drops of clear liquid fell onto the rim of Aurelia's cauldron.
No one saw it. Or if they had, they wouldn't have noticed. It was a momentary motion.
Lynnea returned to her seat without incident and began carefully arranging her materials.
---
Aurelia proceeded according to the steps.
The extract grew transparent. Ten more seconds. Five. She picked up the stabilizer.
That was when it happened.
Something burst in the cauldron.
The liquid began expanding rapidly—the next instant, white smoke erupted. The expansion wouldn't stop. The pressure exceeded its limit.
Boom.
The explosion echoed through the entire classroom.
She was blown backward. Her body flew through the air, and her back slammed against the stone wall. Glass shattered as shelves collapsed. Students screamed. Someone dove under a desk.
She hit the floor. Her back throbbed with pain. Smoke filled the space.
"[serious]Protego——!"
Snape's voice rang out. A series of protective spells deployed, stopping the scattered debris mid-air. The white smoke that had risen to the ceiling was gradually pushed toward the walls.
The classroom was half-destroyed. Collapsed shelves, broken vials, scattered materials. Students stood frozen in the smoke, unable to move.
Aurelia sat on the floor with her back against the stone wall.
(It hurts.)
But that wasn't all.
The sudden impact and explosion had flipped a switch.
Deep in her chest, the Obscurus stirred awake.
Control it, she thought. Clamp down on the emotions. But this wasn't about emotions anymore—pain and confusion had become the trigger. It was harder to control than usual.
The shadow stretching across the classroom floor moved.
In the opposite direction from the light source. It writhed slowly, like something alive.
The window glass fractured in a radial pattern.
Cracks spread with soft, tinkling sounds.
All the torches on the ceiling swayed at once.
In the smoke, the students noticed something was wrong. They froze. Someone let out a small "huh?"
(Stop it.)
Aurelia gritted her teeth. Feeling her nails scrape against the stone floor, she pushed inward with all her strength. Grabbing each emotion by hand and crushing it.
"[cold]Silence"
Snape's voice was low and sharp. Restraining spells layered on top of each other.
It took ten seconds.
The shadow went still. The fractured glass stopped spreading. The torches settled.
Everyone in the smoke was motionless.
Then a voice rose.
"[crying]Professor, I'm scared! She made it explode!"
Lynnea had stood up. Tears glistened in her golden eyes as she continued in a trembling voice.
"[scared]The shadows were moving! It wasn't normal! I saw the smoke come from her cauldron first!"
Other voices followed.
"That's right, the smoke came from Aurelia's cauldron first——"
"The shadows were weird, definitely——"
"It was scary, so sudden——"
The voices cascaded. Six, seven students. All pointing in the same direction. Toward Aurelia.
Snape didn't move.
He kept the entire classroom frozen while looking at Aurelia once—just once.
In that moment, something flickered in his eyes. A certainty that this student couldn't have done this deliberately flashed across his face—then vanished. The teacher's expression returned to normal.
Aurelia saw that moment.
(You're the only one who doubts.)
She understood that. But she also understood that it wouldn't help. Everyone was giving the same testimony. There was no physical evidence of contamination. In this room right now, who would believe Aurelia?
Snape looked away.
"[cold]Everyone, leave the classroom. Class is dismissed"
---
Dumbledore's office was up a spiral staircase. Portraits of former headmasters covered the walls. The fire in the fireplace flickered red.
Snape didn't definitively name Aurelia as the culprit. He simply reported the facts. There had been an explosion. Shadows had moved. The window glass had cracked. Eight eyewitness accounts.
Dumbledore listened to the report and fell silent. He steepled his fingers and gazed into the flames.
"A week's suspension, then."
Snape said nothing.
In the corridor outside the headmaster's office, his footsteps stopped.
He stood facing the stone wall. His right hand slowly formed a fist. He squeezed hard. His nails dug into his palm.
One second. Two seconds.
Then he released his fist and continued down the corridor.
---
When she returned to Slytherin, the atmosphere in the corridors had changed.
Students she passed deliberately made way for her. They pressed themselves against the walls, averted their eyes, pretended nothing was wrong. But that "pretending nothing was wrong" said everything.
She opened the common room door.
Nearly thirty students were inside. None of them turned toward her. Conversations continued. Laughter sounded. But everything—all of it—avoided looking in her direction. As if no one were there at all.
Across the room, Lynnea was surrounded by friends.
"[gentle]Today was really something, wasn't it? It was scary"
Her voice was full of concern. Those around her responded with "Are you okay?" and "That was scary." Lynnea smiled reassuringly in the center of the circle.
In the depths of her eyes, there was satisfaction.
Aurelia saw it. She saw it clearly.
But she could do nothing.
She walked to the farthest corner of the common room, to the stone wall. She sat on the sofa. She hugged her knees.
The sounds of the common room grew distant.
(I didn't do it.)
She knew that. Her procedure had been precise. Her materials had been precise. So why had it exploded? She thought she understood the cause. But she couldn't prove it.
(No one will believe me.)
It was the same as Durmstrang. An explosion had happened in the practice room there too. The student next to her had said the same thing: "Her magic is weird." The teacher had run away then too. She had been left alone then too.
It was the same everywhere.
That thought began circ