Shigaraki sat against a pink membrane wall, arms outstretched on his thighs, palms limply turned towards the ceiling.

Veins ran from the walls and wrapped around his neck and forearms, fine threads breaking off and burying themselves in his flesh.

Nezu knew from the last director of the Commission that it wasn't painful: on the other hand, he also knew that no one really knew what it was.

Tartarus was one of the many anomalies that had appeared at the same time as Quirks : it was an organic, living mass that fed on and devoured any living being that remained within its reach long enough.

It would plunge its captives into a state of dreamlike euphoria, gnawing away at them until they were as meek as lambs.

They would die after a few months, consumed by ecstasy, but not before the Commission had extracted as much knowledge as they could out of them.

- Hello Shigaraki

The young man did not move.

- I'd like to ask you a few questions about All for One.

He tilted his head to one side, his eyes wide open. His mouth, pasty, had all the difficulty in the world to function.

- Sensei... Sensei...

Shigaraki continued to look left and right as if the man would appear out of nowhere.

- You said you'd come for me...

Shigaraki burst into tears.

Nezu watched him, unperturbed, sensing an opportunity.

- He has abandoned you, he said. He is the reason why you are here.

Shigaraki shook his head with less conviction, his chin rubbing against his chest as he moved.

- No, no... I'm here because one of my own betrayed me...

His tongue slipped from his mouth, grazing the hollow of his chin, his head following the gesture as if weighting heavily.

- It was your body he desired before, wasn't it ? It was you that All for One wanted to inhabit

Shigaraki rolled his shoulders and managed to sit up, pushing his tongue back into his mouth with a tired hand.

- I recognise you, he murmured. I know your voice. You're the failed lab experiment, aren't you ? The thing that acts like a human...

- Where's hiding All for One ?

Shigaraki didn't answer, chin up, head against the wall, mouth slightly open.

His glassy, haggard eyes could see nothing, as if he were already dead.

- You gave it to him, didn't you ? The video of the boy

Nezu stood as still as a statue.

He felt the camera pointed at him with the same intensity as if a whole crowd of people were watching him.

- What video ?

A silent laugh shook Shigaraki, his shoulders jerking against the pink membrane wall.

- Sensei was right. It's a good thing you're just a rat without a Quirk, because otherwise you'd be the most dangerous of them all

- What video are you talking about ? Nezu insisted. Which boy are you referring to?

Shigaraki stopped laughing but continued to smile, his cheek resting on his shoulder.

- I thought he was going to kill me in the police station. He grabbed me by the throat and held me like this

Shigaraki raised a limp arm and pretended to strangle someone with one hand. Then he let his arm fall dry against his thigh.

- He didn't hesitate, you understand ? I know he also didn't hesitate when he killed Twice and all the others.

Nezu opted for silence, hoping that Shigaraki would continue to talk and let him learn things he didn't already know.

- Do you think he'll hesitate when he'll learns that everyone knows about his Quirks because of you?

Nezu had never been more aware of the presence of cameras than at this moment.

- Shoto? Are you talking about Shoto Todoroki?

- Sensei said he was a threat because he was strong but had no purpose

A trickle of saliva ran from Shigaraki's lip to his chin.

He continued to speak, eyelids down, eyes staring into the void, spraying his shirt.

- He said that his weakness was his father, but that we shouldn't pick on him until we knew for sure what his abilities were

Nezu had easily deduced that, but he was surprised by All for One's interest in the question.

- Why is… Sensei so interested in Shoto?

- Sensei... it's something the doctor said

Nezu tilted.

- All Quirks come from somewhere, you understand ? He said you could make a genealogy of Quirks starting from the children all the way back to the parents to the grandparents. He did the same for the boy.

Nezu felt a mixture of excitement and worry that made him nervous.

- Are All for One and Shoto Todoroki related ?

The scientific implications of such a breakthrough...

- I don't know. Maybe. Maybe not.

- What was the doctor trying to do?

- He said... he repeated that if the All for the One took, the One for All gave and the boy created, then by combining the three, we could reach the Origin of Quirks.

Nezu froze in astonishment.

The Origin of Quirks was a purely speculative scientific theory based on the history of the appearance of Quirks : it was assumed that the time between the very first Quirk and the possession of such a power by over 90% of the population was far too short to be the result of the evolution of a single mutated individual.

The Origin of Quirks was based on the premise that there was a primordial individual, an Original Adam, who would have carried all the Quirks and all their possible variants, and that from his blood the powers would have been divided and distributed among his descendants.

Genetically speaking, all individuals endowed with Quirks carried the gene for the Origin of Alters: on the other hand, only a combination of very specific alleles was activated in each, which explains why an individual had only one Quirk or - in very rare cases - at most two.

If the origin of Quirks really exists, it means that any Quirk can be created synthetically...

Nezu, feverishly drunk on the revelation, felt his blood heated by pure adrenalin rush to his head.

He held on to the thick glass that separated him from Shigaraki, blinking rapidly to dispel the dizziness that had taken hold of him.

Synthetically create Quirks and grant them to whomever you want...

Head bowed, a wide smile revealed his small rodent teeth, giving him the frightening air of someone about to commit a crime.

He didn't care if the Commission knew what he had just learned since they didn't even know what One for All was.

But Nezu didn't want to give them any more food for thought than they already had: he pretended to rub his face with a paw and stood up with his mouth open in astonishment, looking as if he had just learned that he was going to die.

Unauthorized reproduction: this story has been taken without approval. Report sightings.

- But that's impossible, he muttered. The Origin of Quirks can't even be scientifically proven

Or at least undemonstrable given the ridiculous level of current superhuman DNA sequencing.

Shigaraki smiled almost lazily.

Nezu's heart began to pound furiously against his chest.

- Does All for One have the means to create it ? Can he reproduce the Origin of Quirks ?

If All for One has such a weapon between his hands...

Shigaraki's head rolled from one shoulder to the other, as if to say 'no'.

- If he could do that, you'd all be dead by now.

Nezu felt his heart slowing.

- But that doesn't mean he won't try.

*

Ochaco, towel in hand, absentmindedly dried her hair.

She leaned against the corner of her desk, her eyes glued to a mathematical formula she'd been trying to memorise for far too long.

She reached for the apple on her desk and bit into it, the sweet juice running down her chin.

She wiped her lip with the back of her hand, her eyes never leaving the paper as she nodded at each new line of the demonstration she read, trying to take it all in.

She ate the apple in silence, the sound of the clock clicking steadily in the background, and-

Wait a minute. Since when did Ochaco have a clock in her room?

Surprised, the girl looked up at the wall on the other side of her bed.

There was no clock.

But the seconds were ticking away on the blank wall.

Ochaco put her apple on her maths sheet and carefully crossed the distance to the wall.

The ticking increased. The clock seemed to be inside the wall.

Ochaco raised her hand hesitantly.

She brushed her fingertip against the wall and felt it vibrate like a beating heart.

Suddenly there was a howl from the bowels of the building and the wall shuddered under the fists of someone trying to escape.

Ochaco stumbled backwards and fell, her chest rising and falling rapidly, recoiling onto her buttocks, her eyes riveted to the wall, which vibrated like the shimmering surface of water.

With each new blow, the wall lost its consistency, becoming as thick as milk and as supple as elastic.

Ochaco saw a fist strike the wall, the imprint of his fingers in the thick liquid. With each new blow, the whitish fabric expanded like the roof of a tent, the thing trapped within the wall pushing against it again and again until a whitish pyramid was formed.

Pale and wobbly, Ochaco crawled backwards.

She raised her hand to the thing coming out of the wall, ready to use her Quirk, but nothing happened.

Terrified, unable to understand what was happening, Ochaco's back hit the foot of her bed.

The thing continued to press against the wall, its body glued to the white canvas that covered it like a second skin.

An ovoid skull continued to push against the wall, then a wide open mouth - as if screaming - appeared, and suddenly long hands with unnaturally slender fingers at the end of arms, bent like the mandibles of an insect, pushed the wall back violently.

The thick veil moved abruptly forward, and suddenly the creature disappeared behind it.

Throat dry, hands clammy, Ochaco lay trembling against her bed, knees bent.

The wall, smooth and thick, had advanced a good half meter, stopping at the end of the rainbow carpet, barely big enough to encompass both feet of her bed.

Ochaco waited, heart pounding.

The wall remained motionless, smooth as stone.

Ochaco raised her hand again, Quirk activated.

The wall didn't move.

She faltered, then finally touched it.

The wall vibrated at her touch, like the shimmering surface of a pool when a stone is dropped into its midst.

Ochaco stood still.

The wall did not move.

The thing screeched and threw itself against the wall.

The wall buckled and the hooked fingers pounced on Ochaco, mouthfuls of fangs tearing through the canvas.

Ochaco screamed and fell onto her back, her arms clutching her face as bits of canvas and saliva splattered onto her face.

The fangs were a hair's breadth from her throat.

Suddenly Ochaco fell.

The thing let out a howl of rage, then tried to grab her with its clawed paw.

But Ochaco continued to fall into a black hole, the window of the howling monster fading like the headlights of a car in the night.

She fell violently onto her back.

Her breath caught in her throat.

Jolts of electricity shot between her vertebrae, making it painful to breath.

Ochaco rolled onto her side and propped herself up on one hand, breathing through her nose until the pain subsided.

The floor under her fingers was black and cold.

She cleared her throat, felt her breathing return to more or less normal, then massaged her neck with one hand as she looked around.

There was no horizon, no sky : everything was black and still.

Ochaco looked up at the window of light, hundreds of metres into the sky.

The thing was gone.

Ochaco staggered to her feet.

The sound of her footsteps echoed in the void.

Suddenly, Ochaco felt her stomach growl.

Then something rose to her mouth.

She put her hand to her throat and suddenly her gullet tightened violently.

Ochaco bent over and vomited all over her feet.

Maggots spewed from her mouth and fell in layers on her shoes.

They swarmed, alive, wriggled against her and began to crawl up her legs.

Ochaco screamed and began to push them away with loud slaps on her shins.

She jumped to escape, but another convulsion split her in two.

She regurgitated a mountain of bloody maggots.

The two groups merged into one, crawling along the floor, up her shoes and arms.

Ochaco tried to activate her Quirk again.

The maggots stirred and swarmed, damp against her skin.

Ochaco screamed.

Then she blinked, and suddenly she was back in the middle of her room, standing at the foot of her bed.

Facing the wall where the heartbeat had come from was Shoto Todoroki.

*

Author's note :

Wanted to portray what it would feel like to be caught in a Genjutsu without knowing.

Pretty sure you'd feel as if you were in a nightmare, hence the title.

Tell me what you thought of the chapter in the comments, if there are things that were not clear enough/could be improved

If you want to support the story/read up to 27 chapters ahead of schedule, then go check the story's P@treon, Nar_cisseENG

See you in the next update everyone !