Prologue

It happened one night.

Jaune Arc had left his home in order to enter Beacon and realize his dream, becoming a Huntsman. Because, against all odds, the transcripts he had asked to be forged had been accepted by the Headmaster.

He'd been walking for two days now. His village was in a rural area, so he had to walk a bit to reach the city of Vale. He should be there by the end of the week.

That night, he didn't find anywhere to sleep. Because of his inexperience in traveling, he didn't plan out his journey correctly, and now he was stuck walking outside in the night until he reaches the next town.

The road was going along the edge of a forest to the right, while to the left spread large grasslands.

Jaune sighed tiredly as he continued his walk. It shouldn't be too long until he reaches the next town now if he was reading the map correctly. At least it wasn't raining, and the night was lit by the shattered moon, so he could still see decently.

Suddenly, he heard a whistling somewhere to his right. He froze and stared suspiciously into the trees.

It was quiet for a moment until there was a rustling noise against leafs.

Animal or Grimm? Something was moving in there…

Jaune let go of the map, and slowly drew his sword, Crocea Mors. Well… More like the sword he had borrowed from his family.

As the rustling from the bushes was coming closer and closer, Jaune deployed his shield and made some more distance between him and the trees, stepping into the grassland, while still keeping his eyes on the bushes.

The whistling came back and stopped at the edge of the forest.

"..."

There was a moment of silence. As if even the various nocturnal animals from the forest held their breath.

Then something suddenly jumped out of the shadows towards Jaune, red eyes flashing and whistling loudly as it was flying towards him. In a panicked cry, Jaune shut his eyes closed and raised his shield without taking the time to identify the threat.

A little 'clunk' noise resonated.

"...Huh?"

Jaune blinked. Where was the Grimm? What was that pathetic impact on his shield that didn't even phase him a little? He looked around cautiously, trying to find the answer.

It was right in front of him.

A little snake, struggling on the ground. It was black skinned, had red eyes, and was so small it could fit in his hand.

Jaune released an explosive sigh of relief. "Just a snake… Phew, scared the crap out of me!"

He relaxed and raised his sword to strike the damn snake.

The moment the blade came down, the snake rolled out of the way before suddenly jumping to his hand and biting it viciously through his leather glove.

Jaune screamed, letting go of his sword when intense pain traveled through his arm. He fell on his ass and caught the beast with his left hand, tearing it off his hand.

The pain didn't subdue. If anything, it increased.

The snake was now evaporating into black smoke in his hand, so Jaune threw it far away and focused on his right hand as he let a low, distressed whine of pain. Had it been poisonous? He removed his glove and rolled up his sleeve.

There was a big hole in his hand. Blood was leaking out abundantly.

Jaune screamed again as another wave of pain spread through his arm and screamed even louder when he saw his hand had started to become black. Something was digging through his arm, a little bump under his skin slowly making its way to his shoulder! Whatever it was, he knew he couldn't let it reach his body. It had already reached past the elbow!

In a desperate move, he bit in the strap holding the piece of armor protecting his shoulder, and gripped the other end with his left hand, before pulling with all of his strength, squeezing his arm hard.

The little bump traveling under his skin reached the strap and stopped. Jaune prayed whatever god existed that it held the thing back.

The thing struggled against it. Was it using his bloodstream to spread? That would explain why it couldn't get through. His arm would have turned blue by now if it hadn't already turned completely black! Grimm black… Jaune let out a distressed whine again as he stared at the parasite struggling stubbornly in his arm.

Slowly, seconds passed, and it stopped fighting against the wall before him.

Jaune held his breath. Was it over?

Suddenly a screeching sound came out of his arm, and a red circle with weird angles and an eye in its center appeared around his arm, rotating around it. What was that! Jaune didn't know, but it looked like a glyph or a blood rune or an evil magic circle from a video-game!

Pain swarmed him again tenfold, and Jaune screamed again, except he didn't hear himself scream. The edge of his vision slowly became black, and he fainted.

"...id? Kid, ...ke up! W… up!"

"Hm…?"

"...ke up! You can't stay here it's dangerous!"

Someone touched his arm.

"Gaaaah!" Jaune yelled as he jumped out of sleep. "Not the arm! NO!"

He blinked, panting and breathing heavily as he noticed he wasn't suffering any pain. It was daytime. A woman was riding a wagon held by horses and was staring at him with scared eyes.

"R-release my husband!"

"Eh?"

Jaune finally noticed he was strangling a man with his right hand.

"I-I'm sorry!" He let go immediately and the man coughed, taking large breaths as he recovered. "Are you okay? I'm so sorry, I must have thought you were... from last night..."

"I'm fine..." The man coughed again and glanced cautiously at him. "You must have had quite the night to be so jumpy! Met a Grimm last night?"

"Y-yeah, well..."

Just a snake actually. He suddenly remembered everything and checked his hand with wide eyes, expecting to find the black claw of a Grimm.

But no, his hand was normal. Even the hole had disappeared.

Had it all been a bad dream…? Maybe it went away because the parasite didn't reach his brain? If so, did it die?

"I'm so sorry..." Jaune apologized again when he noticed the couple staring at him. "I… I had a rough night and… I think I passed out on the road."

A pitiful excuse, but the two farmers still smiled.

"Come on, young man." The man offered his hand, and Jaune took it gratefully, stumbling a little after being pulled up. "Wait a second..." He walked to the back of his wagon and picked up something.

"Eat this, you'll feel better." He threw an apple to Jaune.

"Ah… Thank you!" Jaune smiled gratefully, only now realizing his hunger.

Jaune devoured the apple under the couple's gaze. Then he was offered another. He ate it again. It seemed the wagon was transporting huge bags of apples.

One after the other, he ate a dozen apples. And he was still hungry afterward.

"Gods," the woman laughed, "It must have been a while since you ate something! I've never seen such appetite, even from my son! And that's saying something."

"I'm sorry..." Jaune scratched his hair and kept himself from asking another one.

That's odd, I never ate so much before.

He took out some Lien. "I can pay you for that, here..."

"Keep your money, kid. You need it more," The man grunted, waving it away. "Travelling at your age, where are you going?"

"I'm heading to Vale. I want to enter Beacon become a Huntsman." Jaune smiled honestly.

"Huntsman, huh?" He considered him carefully, looking him up and down. "Well, we're not going to leave you alone in the middle of nowhere, we can at least take you to the next village. You can sit at the back of the wagon!"

"A-ah, are you sure? Thank you very much! It'll let my feet breathe a little!" Jaune grinned, internally cheering.

After sharing a little laugh with the two farmers, Jaune picked up Crocea Mors and his glove and climbed at the back of the wagon. Just like that, he was taken to the next village. On the way, he talked about his ambition to the two farmers, and they gave him information on the area, otherwise making small talk. Sometimes, he checked his right hand, not quite sure it was back to normal.

Unknown to him, however, an eye was appearing on his hand when he wasn't looking. It was discretely observing and analyzing its surroundings, listening to the conversation…

The day after.

The couple of farmers had offered him a room in their house and he had spent a wonderful night as he met and talked with their family. Strangers are really just friends you haven't met yet.

Now Jaune was back to walking on the road heading to the city of Vale. Four more days and he should arrive. The first day of Beacon was nest week, so he'd have a bit of time before the lessons begin. Maybe he should find some books to get more information on Huntsmen and their training.

His right hand had been normal. The only thing bothering him was his bottomless appetite. He knew he'd always eaten a lot, but it was never to that degree! It was like he ate for two… Or even more.

A low growl came out of his right.

Jaune turned around, drawing Crocea Mors and deploying his shield. After the night last time, he'd become a bit paranoiac, jumping at every noise, but he was sure he didn't imagine that one.

This time it was a Grimm. A wolf type, judging by the way it moved, his claws and pointy teeth.

It noticed him and began approaching cautiously, letting out a low growl. Jaune took a step back.

I'm not ready for this. This is too early!

It was just a small Grimm, probably the weakest of all Beowolves, like a puppy. It was enough to scare Jaune, however.

He deployed his shield and hid behind it. He held his sword back ready to strike. The plan was to let the Grimm strike first, tank the hit with the shield, hopefully, push it back and get in a slash with his blade. Then repeat.

Easier said than done… He didn't know how to take a hit with a shield. Should he block or deflect?

Or maybe I should just run?

No, his cardio and stamina were pitiful, not to mention his speed. Also, the next town was too far.

Suddenly the Grimm roared and charged him, interrupting Jaune's thinking.

Crap crap crap crap…

Despite the fear he felt, Jaune steadied his feet on the ground, lowering his posture instinctively to better tank the blow.

The Grimm jumped on him, slashing at his left side. Jaune managed to block the blow but stumbled back to not be crushed under the monster.

Faster than he expected, the Grimm followed his attack by another slash of his right claw to his right side. Jaune raised Crocea Mors and managed to deflect it, but his grip on the sword was too weak and he got disarmed!

He desperately blocked with his shield a second blow coming for his head, before another followed from the other claw, which he couldn't dodge.

The claw came towards him, and Jaune shut his eyes, tensing his body for the unavoidable agony coming…

It didn't come. Instead, there was a loud whistle and a sound of flesh being torn apart.

Jaune opened his eyes.

The Beowolf was staring at the sharp claws stabbed into its chest. They clenched and tore apart the Grimm's body.

"W-wah..." Jaune gaped at the claw and realized it was his right arm. "Waaaah!"

As the Grimm fell and started disappearing in black smoke, a red eye popped on the back of the claw - his hand ! - and looked around curiously, before settling on Jaune.

Naturally, Jaune screamed, causing the eye to disappear and his arm to revert back to normal making a weird sound.

Zzzzzzzzzzu.

Jaune gasped, breathing heavily as he poked his right hand and swung it around. "T-this… this is not my hand… What the-?"

He grabbed Crocea Mors. He was going to slash his hand, to see what color the blood was. To confirm he wasn't crazy. To draw this… thing out!

Just as he was about to cut his hand, it reverted back to a claw at amazing speed and held the blade back.

Jaune gasped as under his eyes, his right arm transformed into a monster from nightmares. Three tentacles shot out of his arm, which at the end of each a red eye appeared. A hole dug itself into what was supposed to be his hand, forming a weirdly human mouth.

"..."

Actually, it looked like he was waving a Grimm puppet in his hand. You know, the ones you could make growl and bite by waving your fingers.

"Zone..." It spoke!

"Wha! What are you?! What did you do to my hand!" Jaune screamed, terrified.

"Zone..."

"Z-Zone?" Jaune repeated, trying to understand the thing.

"N-no. Zone..."

"W-What zone?"

"Zone… y-you. No g-goo-od… talk y-yet."

"Me?" Jaune laughed madly. "Zone… You mean Jaune!"

"Z-zone."

"It's Jaune. Jaune!"

"Zone!"

"..." Jaune stared at his hand with wide eyes, amazed at the situation despite being scared. His hand was talking to him and was calling him Zone.

...Why am I talking to this thing?

"Z-Zone, no hurt. N-no... go-ood."

"Y-you… What did you do to my hand?"

"Failed… e-at Z-zone… Onl-ly arm."

"You wanted to eat me! Wait, you ate my arm?! Are you a Grimm?"

"D-Don't know… tired. Sle-eep now... Zone, no hurt... e-at m-more."

Zzzzzzzzzzzu...

With a strange whistle, Jaune's hand reverted back to normal.

"A-ah..." He breathed loudly, poking his right hand with his left. "H-hey… Don't go to sleep! Tell me more!"

He shook his hand again. It didn't respond.

"Y-you… Wake up!" Jaune growled angrily and tried to cut his hand again.

In an instant, his right arm turned back into a claw, grasped the blade from Jaune's left hand and threw it.

It landed ten meters away.

"Zone n-no hurt… Sle-eep."

Zzzzzzzzzu.

With a weird sound, it came back to normal again.

"A-ah..."

Okay… So maybe it was a bad idea to hurt his own hand. No, it wasn't his hand anymore! But what was it? A Grimm? Then why would it kill the Beowolf?

Jaune's eyes widened as he stared at his hand.

"… C-Could it be… It saved me?"

In the evening

When Jaune arrived in the next town, he immediately rent a room at an inn and went to a library to research information on books. He could have used his scrolls's internet, but the information wasn't viable and things like Grimm and Huntsman training weren't released online.

" Do you have a book on talking hands?"

The woman stared at him from behind her desk.

"...No."

Figures.

"What about books on Grimms?"

"Last row, check in the far back." She pointed.

"Thank you."

Jaune went to the designated area.

"Hmm? Ohh..."

There were a reasonable amount of books on Grimm. He checked the first that grasped his attention: 'Grimm Encyclopedia'.

Jaune sat on a nearby table and hummed as he read the thick book.

Grimms: Creatures of destruction, lacking a soul, they have sought to destroy humans and their creations forever…

…However, humanity keeps succeeding in protecting civilians and keeping the Grimms at bay, thanks to Huntsmen…

"But my right-hand doesn't want to kill me or any humans." Jaune mumbled to himself and crossed his arms. "On the contrary, it actually saved me and killed a Beowolf..."

Did it mean the parasite in his hand wasn't a Grimm ? No, the red eyes, black skin and white bones, there was no mistake… It had to be a Grimm.

…drawn to negative feelings such as envy, sadness, despair, hatred, anger…

"Hmm..." Jaune skimmed through the various species of Grimm, and researched the term parasite on the site. He never researched it before, but it was probably a good idea to know about the most common Grimms if he was going to enter Beacon.

Jaune rapidly browsed over the various species of Grimms. There was a lot. "Come on… ah, there!"

Geist: A special type of Grimm resembling a ghost. It is capable of 'possessing' inanimate objects.

It is one of the multiple variants of possessing-type Grimms.

A Geist is called differently depending on what it possesses:

- Rocks: Petra Gigas

- Armour and/or weapons: Arma Gigas

- Tree or any wood: Arbor Gigas…

Jaune let out a sigh. He was not an inanimate object, he was a human, and very much alive! He skipped through the end of the page and read.

There are no recorded cases of a possessing-type Grimm capable of possessing a human.

"Dammit… What am I supposed to do?" He lamented as he checked several other books. Nothing talking about human possession.

"Ugh..." Jaune leaned back on his bed, feeling the fatigue of the day kick in.

He took a few books with him to the inn, including one on basic Huntsman training, promising the woman he'd give them back tomorrow.

As he walked back to the inn, he thought.

Should he talk about it to someone?

'Hello, my name is Jaune Arc, and a Grimm is possessing my right hand, could you please help me find a solution? Hm, me? No, I'm not possessed. Just my arm. Please don't kill me. Ah, I'd also prefer to not spend my life in a lab as an experiment sample if possible… Also, can I become a Huntsman?'

"There's no way I can talk about that to anyone…" Jaune sighed.

He spent a couple more hours researching additional info in the books but didn't find anything relevant.

In the end, Jaune fell asleep on a book, tired physically and mentally.

In the morning

Drrrrrri… Drrrrrri…

Jaune groaned under his covers and pillow as the alarm rang. Seven am… It was a bit early in the morning but there was still a long way until he reached Vale.

Drrrrrri… Drrrrrri… Tic.

Hm? Why did his scroll's alarm turn itself off?

Jaune sat up on his bed and groggily looked at his bedside table.

He blinked.

There, a weird little monster was examining his scroll with curious blue eyes.

"I see, with this... you wake up... at certain time..." It mused.

Jaune blinked again.

"WWOAAAAH!"

He screamed and the Grimm turned to him, jumped to him.

Zzzzzzzzzzzzzzu.

"Wha- what the-?" The Grimm turned back into his normal human hand.

Someone knocked on the door.

"Is everything okay?" A woman's voice came from behind.

"A-ah, yes! Just a nightmare… I'm sorry!" Jaune apologized to the woman who had opened the door and glanced inside.

"That's a relief. Be quieter, please. Some people are still asleep." She groaned and closed the door before leaving.

"Phew..." Jaune sighed and eyed his hand warily.

A blue eye popped into existence on his palm, followed by a mouth. Then Jaune's arm extended like a snake and his right hand reached the ground, forming little feets and walking around while still connected to his shoulder.

"You..." Jaune was at a loss for words.

"I have used your… sleep time to learn... more about... our species."

"You know how to read?!" Jaune gaped and noticed several of the books layed out on the ground. His right hand picked up his scroll again, and unlocked it using the correct password.

"I learned... last night."

"So you were doing this last night too..."

This thing… maybe Jaune should go to the police after all? It seemed to be learning very fast.

"You took my right hand!" Jaune accused suddenly.

"Yes, I failed... But focus... on current situation. Right now... need each other..."

"Need? I don't need you." Jaune scoffed. "I can cut off my arm if I want to I wouldn't die! I can get a prosthesis or something."

"That's no... good, Zone..."

"It's Jaune."

"If not connected to... body, I cannot receive... necessary nutrients to... survival. I die quickly."

"Don't care. You ate my right arm and you're a Grimm!"

One of his eye on top of a finger turned to look at Jaune. It then looked away, seemingly thinking.

" I leave you...control of... arm. And defend you... against danger? Like that... you can... be Huntsman."

"How do you know about that?"

"I listen, Zone..."

"Jaune."

He wriggled in the air. "If you tell... You be treated as... enemy of your... species, or as... sample for... experiment. Like that, you not Huntsman."

"A-ah… That's true." Jaune admitted.

"Zone."

"Jaune."

"We're... enemy to both... species. Need... cooperation for... survival."

"I'm not an enemy of humanity!" Jaune protested. "And, don't you want to kill humans? I thought you were a Grimm."

"Don't... know. Want to... survive, you survival... necessary. I can protect... against Grimm... Humans too..."

As it said that, Jaune's hand became black and formed sharp blades and claws, eye turning red.

"How... about it?" His hand asked, eye watching Jaune.

"U-uh..." Jaune hesitated, intimidated.

Zzzzzzzzzzzzu.

It must have sensed its fear, because it turned back into a normal hand, except for an eye which he turned to blue and a mouth in the palm. It was the same blue as Jaune's eyes, he remarked.

Jaune stayed quiet for a moment, before standing up and deciding to take a shower to have more time to think.

The mere idea of working with a Grimm left him disgusted, to be honest, but what choice did he have?

Jaune winced as he poured cold water on his face. That was refreshing and made sure to truly wake him up!

"Zone, cold! Too cold!"

"Endure it."

"Human anatomy... What purpose... of this, Zone?"

"Wha- H-hey! D-don't touch that! S-Stoooooop!"

Ahem... Where was he? Oh yeah, his possible decisions.

Talk about it? Like his hand said, chances are he wouldn't be able to become a Huntsman because of the parasite. It was selfish, but deep in his heart, he really wanted to pursue his dream of becoming a Huntsman, despite having a Grimm in his arm.

In the first place, if he talked about it to someone, the parasite would probably keep him from doing so. Maybe by killing whoever he tried to talk to, or even injuring Jaune himself.

No matter what, there was still that possibility. That his hand would kill him. It was a Grimm after all.

Then... Cut off his arm? But... It was his arm! And like before, the parasite probably wouldn't let him. Also, he couldn't tell for sure when it was truly sleeping or not.

...Even if it's cut off, it'll probably reattach itself to Jaune like he did just before when his hostess came to check up on him, wouldn't it... No matter what, it was too dangerous, and he really wanted to keep his arm.

So... He was screwed? There was no way out of this. He'd have to work with a Grimm...

Well. At least it didn't really feel like a Grimm.

"… I suppose we don't have a choice." Jaune grudgingly accepted as he left the shower and put on his clothes after drying himself. His right arm let out a low whistle when Jaune dried it with a towel.

After analyzing his options in his head, he felt strangely calm regarding this whole situation. He was pretty sure he should have had a panic attack by now, but instead, he was rationally thinking things through.

"...Zone?"

"Okay, let's cooperate, but we need to set a few rules."

"… As expected... of human. Intelligent. Organized."

"Flattery doesn't work on me," Jaune warned, eyes narrowing.

Well, not when it came from a Grimm. When it came from girls, however? It worked too much.

"First, let's give you a name."

"… name?"

"Yes. I can't keep calling you 'you' or 'right hand'. For example, my name is Jaune."

"Zone..."

"I told you it's Jaune! Not Zone! JJJaune!"

"That is... what I said...?"

Jaune's eye twitched. "Well, fine. From now on I'll call you…" Jaune checked and typed something on his scroll, "Manus!"

"Manus…?"

"That's right. Because you are my right hand! Manus means hand in the ancient language, I just checked the dictionary."

"Call me... how you want." Manus made his eye disappear as if disappointed. Or he didn't care?

"Second," Jaune thought for a bit, "We need to make sure no one sees you or learn your existence."

"I... agree."

As he made preparations for leaving once again, Jaune couldn't help but feel he was reacting way to calmly at the current situation. But, what choice did he have, really? As long as Manus didn't want to kill anyone other than Grimms, it was better than reaching for someone else and risk both their lifes and his...

"Never kill a human, okay?"

"What if... threats survival, Zone?"

"We render him unconscious by knocking him out. I want to avoid killing anyone. That's absolute, am I clear?"

"Why... Zone? We killed Grimm... Why no Humans?"

"U-um, Grimms are mindless and want to kill humans unconditionally," Jaune explained carefully. "Humans, however, don't want to kill us. Even if they try, there are always other ways to deal with them. We, humans, lock the ones that kill people away for a long time so we must not kill anyway. All right?"

"I don't... understand, Zone. I no mindless."

"You're not..." Jaune nodded hesitantly. "So you will understand in time. You're smart." I waved it away.

"..."

Manus stayed quiet, probably struggling to understand human logic.

"If someone... learn about me... or want kill us... We kill him." He stated.

"You can't!" Jaune gasped. "I told you..."

"This is... my rule. No one... must know. Could threat survival..."

Jaune grit his teeth. If they were going to work together and set rules, he knew he'd have to make a concession. That parasite was way too smart for a Grimm one day old.

"F-Fine. But only if it is strictly necessary and really threatens our survival! Understood?"

"Yes, Zone."

"And you have to constantly hide when there are people around! Okay?"

"Yes, Zone."

"Hmph..."

Jaune took a deep breath to calm himself down. Just now, he raised his voice a little, that was no good. One should always stay calm during negotiations.

Again, he noticed he was way too calm. Perhaps the parasite didn't affect only his arm. No, no, there was no way.

"You'll need to follow Human laws too." Jaune eventually said.

"Human laws?"

"Things like don't rob, don't kill, don't injure others, don't go where you're not supposed to..." Jaune enumerated.

"… I don't ... understand, Zone."

"Don't worry. You'll figure it out. With time."

"..."

"Strangers are really just friends we haven't met yet." Jaune laughed as he looked at the palm of his hand.

Manus's blue eye reappeared in it, narrowed, and turned red. Chills ran down Jaune's spine.

"Do not... misunderstand. Cooperation because... lives are connected. I am no pet... Zone life feeds me... so Zone survival is best. I am Grimm... No sympathy."

"…Y-Yes. You're right."

His hand had been eaten by a Grimm. No matter what, it was still a Grimm. But if he was going to spend the rest of his life with Manus in his right hand, he might as well get along with it and try to work together, right? Crap, if his family learned about it... His dad would kill him. But there was really no helping this situation.

"Tired, Zone. I go sleep..."

Zzzzzzzzzzu.

Jaune felt his hand shift and come back to normal.

Despite what Manus had just said, when he took a quick breakfast, left the inn and departed after giving back the books, he thought perhaps things were not as horrible as they seemed yesterday.

Along the way, Manus asked questions about everything, and Jaune answered as best as he could. When Jaune slept, Manus read things online on his scroll or on the books Jaune could find. It seemed Manus needed about four hours of sleep in a day.

His vocabulary was growing at an incredible rate. He was going to become capable of fluent speech very quickly. It was a bit worrying if Jaune was completely honest.

Manus wanted to know more about his species and insisted on making a few detours to find a couple Grimms here and there along the way. It seemed he could sense his pairs, along with human negative emotions, like all Grimms. So, Jaune accepted to 'study' and kill a few Beowolves along the way, and used the opportunity to get used to fighting Grimm. Several times, Manus could have ended the fight and killed the Grimm quickly, bu Jaune wanted to increase his fighting capability so he asked him not to unless it was absolutely necessary.

Killing Grimm posed no problem to Manus. He didn't care about his species, and he himself didn't feel like a Grimm. All he wanted was to survive. And perhaps learn more about the world.

Like that, they walked and crossed villages and towns, forests and grasslands, until they reached an area with more civilization. Then they took a bus, and finally…

They reached the city of Vale.

What do you think? Forgive my English if you notice weird sentences. I'm not a native.

Obviously, the idea is inspired by the manga Parasyte.

Rated M because I'm parano.