Senku's chuckles filled the air as he removed a bunch of charcoals tied together from a bag, placing them down in front of his friends who watched in a mixture of confusion and curiosity.

"We have the three materials we need to make gunpowder." The scientist explained with his trademark smirk as excited grins broke out on the trio's faces.

"We have them already?" Taiju questioned with sparkling brown eyes.

"That's great news!" You beamed with delight. "So, what do we do now?"

Senku began rubbing his hands together in mad glee as evil cackles fell from his lips, looking very much like an insane scientist straight out of a sci-fi movie. "All we need to do now is mix it. It's time for our happy gunpowder cooking session!"

You sweatdropped while Taiju let out an enthusiastic shout of agreement, pumping a fist into the air. Red orbs met (e/c) ones and Senku winked at you, gesturing to the pile of ingredients to make gunpowder. "And this is where you come in as my assistant lab. Are you up for it?"

Your eyes sparkled with determination, showing that you were more than ready. "I won't let you down!"

Senku's eyes softened as he lifted a hand to pat your head, a small smile shaping his lips. "I know."

Your cheeks flushed a light pink and tore your gaze away from him to glance down at your shoes to hide how pleased you felt, your heart thrilling with happiness. "Mn."

With that, the two of you got down to work.

"Ingredient number one for gunpowder..." Senku began his mini-cooking class, holding up one finger as you poured the sulfur into a large bag. "Sulfur, which we can get plenty of at this hot spring."

Both Taiju and Yuzuriha watched the process with rapt attention as the scientist held up another finger. "Number two...Charcoal. We can get all we need by burning wood. (Name), add a few will do. We don't need that much."

Nodding your head, you tossed charcoal after charcoal into the bag, be careful to not spill any of the yellow powder while doing so.

"And number three," Senku lifted the third finger. "the last, but most difficult: potassium nitrate. It'll take a hell of a long time to make this stuff, so...."

He trailed off before whipping out a bag of white powder, winking happily as he held it out in front of Taiju for him to see. "Kukuku! I've already made some to save us time!"

You couldn't help giggling over how cute Senku looked with his act, wanting nothing more than to pinch his cheeks like you would with an adorable five-year-old.

"O-Oh!" Taiju exclaimed in awe before it was replaced by a frown over how familiar the word was. Furrowing his brows, the brunette wrecked his brain and tried to recall where he had heard it from. "I feel like I've heard the word 'nitrate' somewhere..."

A lightbulb went off in his head.

"Nitric acid!" He finally remembered the mini-lecture he received in the cave as Senku explained that nitric acid came from bat poop. "Miracle water! You got it from that cave?"

"You're right for once, simpleton." The scientist replied with an impressive tone while pouring potassium nitrate into the bag filled with the rest of the ingredients needed to make gunpowder. "Ten billion points for you."

After which, he grabbed a stick and began to mix everything all up while the rest of you watched with anticipation. "Potassium nitrate, sulfur, and charcoal all go in the mix, and a pinch of sugar as a secret ingredient gives it a little more oomph. This is glucose that I made from grapes."

Senku explained and poured the aforementioned sugar into the mix before proceeding to grab a log out of nowhere and lifted it above his head. "Finally, pound it until it's packed solid."

(A/N: PLEASE DO NOT TRY THIS AT HOME OR I'LL CALL THE AUTHORITIES ON YOU! I WILL KNOW AS I HAVE EYES AND EARS EVERYWHERE, SO YOU BETTER WATCH OUT! Okay, I'm just joking, but seriously though, don't try to do this home. Author-san and Senku aren't held responsible if anything happens as you already have been warned. Alright, back to the story.)

Suddenly, a movement could be heard coming from Taiju as all heads turned towards him, only to see him carrying a huge boulder over his head as he yelled out, "Pound it, huh?! Leave the heavy lifting to me!"

"Eh?!" The three of you let out startled cries, staring at the teen with incredulous eyes.

"Are you sure that's a good idea?" Yuzuriha instantly rushed forward and tried to reason with the teen before he did something reckless like causing an explosion. "You might be strong enough to make it spark and go boom! Like flint!"

"Nah, you won't get any sparks by hitting stone with stone." Senku was quick to assure.

"Really?" You questioned with a tilt of your head, glancing down at the seated male with furrowed brows.

Hearing this, Taiju carried the boulder over to another random boulder sitting nearby to test out the theory and just as Senku said, nothing happened. "Oh, you're right."

Smiling, Senku began explaining. "Flint is more than just stone. It needs to have metal in it to make sparks. Hot springs, volcanoes, iron pyrite..."

He trailed off as the phrase "iron pyrite" sank into his mind, his eyes widening in realization that when combined with Taiju's immense strength, it was just a recipe for disaster waiting to happen. "Iron pyrite?! Wai—"

Senku tried to stop Taiju but he was a second too late as the latter raised the boulder high above his head, letting out a loud yell and using all his strength, he hit the bag packed full with gunpowder.

Crackling sounds could be heard and as Taiju moved the rock away to reveal stray sparks, a sense of dread filled everyone as they gathered around the bag full of gunpowder with eyes widened in horrified fear.

It felt like time slowed down as the four quickly retreated for safety but didn't get far enough when an explosion went off and was sent flying backwards from the force alone. Taiju wrapped an arm around Yuzuriha's waist, shielding her with his body while Senku did the same with you, both of them disregarding their own safety to protect their respective partners.

A terrified squeal escaped your lips as you buried your face in the scientist's chest, feeling the heat licking the back of your legs despite Senku taking the brunt of it. The scientist tightened his hold on your figure as both of you landed on the ground, a few feet away from the explosion.

Thick clouds of black smoke rose high into the sky which could be seen by anyone for miles away. The four teens scrambled to their feet, feeling slightly disoriented but they soon recovered as they stared at the burning pile in awe.

Red orbs were glowing with glee over the successful homemade gunpowder as Senku exclaimed, "No problem! Our gunpowder cooking was a huge success!"

"Well, who would've thought it'll work." You scratched your cheek in amazement.

Sweatdropping, Yuzuriha added. "I had no idea gunpowder was so powerful."

"Yeah," Senku agreed. "There've been plenty of accidents where students were experimenting with it and got their limbs blown off. It can easily be lethal."

You let out a nervous chuckle. "Well, thank the lucky stars that we avoided our limbs being blown off."

"We're going to attack Tsukasa-kun with this?" Yuzuriha questioned.

The corners of his lips lifted into a smirk as Senku replied, "No, we're going to make a deal."

The three of you exchanged looks of doubt, unsure if handing gunpowder over to a killer would be a good idea. Senku must have read what was on everyone's mind because he began to explain himself.

"Tsukasa isn't a mindless killer." He stated before turning to address his best friend. "Taiju, remember what he said when you went at him?"

Furrowing your brows in concentration, you tried to remember the conversation between the two of them and once you did, (e/c) eyes lit up with understanding. You held up a finger in contemplation, saying, "In other words, in the right circumstances, we can negotiate with him. Am I right?"

"Good job," Senku replied and you became flustered, as always whenever the green-haired teen praised you. "As long as we have gunpowder weapon, we have leverage."

Both Yuzuriha and Taiju exchanged relieved smiles, but you noticed how Senku was frowning, a troubled look written across his face. Walking to stand by his side, you slipped your hand into his and interlocked both your fingers.

He glanced down at the joint hands in surprise before meeting your gaze with a brow raised in question. With a light squeeze as a silent encouragement, you smiled fondly and said, "We'll get through this together even if our negotiations with Tsukasa fall through. You aren't alone in this, Senku."

Red eyes widened; surprise that you had read him so easily but he should have known better than you could see right through him. You always had and he could never put it into words how much he appreciated you for that.

The words he wanted to express refused to form on his lips, so instead, he squeezed your hand in return and prayed that you would get it, which you did.

'Thank you, (Name).'

The edges of your (e/c) eyes softened and you leaned into his side, the warmth of his body making butterflies fluttered in your stomach as you responded in a soft voice, "You're welcome."

Time skipped

"All right, it has gotten a lot weaker," Taiju commented as he poured water over the smoking pile while both you and Yuzuriha were in-charge of getting more water.

Senku let out a chuckle as he poured another round of water after Taiju, watching as the smoke slowly started to thin out. "If Tsukasa's after us, there's a ten billion percent chance he'll find us."

Suddenly, something in the far distance caught your attention. Glancing up, you squint your eyes to get a better look, only to let out a startled gasp by what you saw.

"Senku, Taiju, Yuzuriha..." You notified your friends who immediately looked over as well and to everyone's surprise, there was a cloud of white smoke rising into the air.

"A smoke signal..." A wide-eyed Senku breathed out in shock.

Yuzuriha whipped her head around to stare at the scientist with worried eyes. "Tsukasa-kun?!"

"No, that's in the opposite direction." Senku was quick to clarify, still unable to tear his eyes away from the scene before him. "Besides, Tsukasa has no reason to reveal his location."

"What is it, then?" Taiju asked. "A forest fire?"

"No, it can't be." You shook your head, frowning as you racked your brain for a possible reason. "It's too well-timed to be a coincidence. It was clearly raised in response to our smoke."

"You mean..." Yuzuriha was beginning to catch on.

"Yeah," Senku replied, confirming her suspicions. "This is exhilarating. There's someone else in this stone world."

"More people?" Taiju questioned, his eyes wide with disbelief that there are other people besides the four of you, including Tsukasa, alive in this stone world.

Turning around, Yuzuriha hurried over to the bag of gunpowder, suggesting, "We have to finish putting out the fire."

"Oh, that's right." Taiju agreed as he, too, turned around to help the brunette but both of them were quickly stopped by Senku who said, "No, hang on. As far as they know, that explosion could have been from a volcano. We need to signal them even more before they leave."

"I see!" Taiju exclaimed in understanding, but Yuzuriha, on the other hand, voiced her concern. "But if Tsukasa-kun is after us..."

"...we'll be doing him the courtesy of letting him know where we are." You finished, a worried frown appearing on your face as you looked over to Senku who was still staring at the smoke signal in the distance. "What do we do, Senku? Put it out? Or light it?"

The scientist hesitated as his mind raced with all sorts of thoughts before finally coming to a decision. "Light it! Fire the smoke signal!"

Without a moment to waste, the four of you got to work by throwing the remaining charcoals to keep the smoke going for whoever had lighted their smoke signal to see.

"We're running out of gunpowder." Senku cursed through gritted teeth and turned to his friends as he instructed them in an urgent tone. "Throw in anything that'll burn!"

You decided to stay with Senku and helped him to keep watch over the fire to make sure it wouldn't burn out so soon as the other two ran off in search for more firewood. "Hang on! I'll go get some wood!"

Rising to his feet, Senku ran a hand through his hair out of frustration while muttering to himself, "It's a double-edged smoke signal. We're letting everyone in the vicinity know where we are. If Tsukasa knows about our plan to make gunpowder..."

He trailed off when you stepped forward and into his personal space, both arms snaking to the back and hugging his upper torso.

"W-What are you doing?" Senku was taken by surprise as his eyes travelled downwards to stare at you questioningly.

Turning your head to the side so that your right ear was resting against his chest where his heart laid, you pressed yourself closer to him when you heard the fast thumping expressing his anxiety.

The two of you stood there in silence (Senku not having much of a choice) until his heart had calmed down, the steady hum of his heartbeat resounding in your ear then did you finally speak up.

"Feeling better?" You asked with a small smile as you stepped back, giving Senku some breathing space.

The scientist opened his mouth, ready to argue saying that there was nothing wrong with him but stopped in his tracks when he saw the knowing look in your eyes. So, with a defeated sigh, he reluctantly replied, "That was completely unnecessary since it barely did anything."

You giggled at his words but accepted his answer as it was, knowing that he was telling the truth. "Well, at least my hug did something even if you disagree."

Senku clicked his tongue, ready to protest when suddenly, the atmosphere in the air changed and the scientist immediately moved to embrace you. Blinking your eyes, you were about to ask what was wrong when you noticed Senku glancing at something, or rather, someone from within his peripheral vision.

You didn't have to look to know who had entered the scene and that sent a shiver down your spine as you willed yourself not to tremble in fear.

Senku's arm, which was wrapped around your shoulders, tightened his hold on you as he let out a chuckle and glanced over his shoulder, staring at the enemy with a sharp curl of his lips. "'If weapons of science enter the scene, I won't be the most powerful anymore.' You look like you're about to throw a tantrum, Tsukasa."

You decided to take a quick glimpse, only for your (e/c) eyes to widen in alarm when you saw who Tsukasa had taken as a hostage and your heart began to race in both worry and dread.

"You could put it that way," Tsukasa smirked in agreement as Yuzuriha trembled in his hold, the sharp tip of his spear pointed at her neck. "If you make weapons of science and revive the older generations, they'll begin fighting over established interests, and we'll be right back in a tainted world. I don't mind getting my hands dirty to stop that."

"So now you have to kill Science Man Senku here, huh?" Senku humoured him, although his eyes held a different story. "America would be moved to tears by your merciful death sentence."

"Yeah." Tsukasa tilted his head to the side and went straight to the point. "But first, would you mind giving me the recipe for the petrification revival fluid?"

A quiet whimper escaped your lips when Tsukasa pressed his spear an inch closer to Yuzuriha's skin, a bead of sweat dripping down the side of her face. Senku, on the other hand, stiffened as he racked his brain for a quick solution, the hand that wasn't holding onto you curling into a tight fist.

"Senku," You whispered, your voice trembling in anxiousness with each passing second. "What are we gonna do?"

Senku furrowed his brows in contemplation before making up his mind. Moving his arm away so that he was cradling your face instead, Senku whispered as he gently ran his thumb over your cheek. "(Name), listen to me. Whatever happens from here on out, I need you to trust me. Can you do that?"

You leaned into his warm touch, (e/c) orbs searching red ones as you asked with a hint of trepidation. "Just what are you planning to do, Senku?"

As his other hand lifted to tuck a stray (h/c) hair behind your ear, the corners of his lips lifted into a small, but reassuring smile. "Just trust me, (Name)."

You bit your lips in hesitation but eventually nodded your head. "Okay, Senku, I trust you."

The smile on his face widened as he ducked to press his forehead against yours, earning a startled yelp from the (h/c)-haired girl beneath him as he watched your eyes enlarged in shock.

He chuckled when he saw your cheeks turning a rosy shade of pink with your mouth gaped open slightly at the unexpected action. His eyes roamed your face once more before he released you and turned to give Tsukasa, who had been quiet all this while, his full attention.

Cracking his neck, Senku shrugged and grinned lazily, saying, "Sorry, but I'm not as merciful as you are. I can only look at things logically. I don't care one millimetre what you do with that woman. There are plenty of females around—"

He was interrupted mid-sentence as Tsukasa moved in the blink of an eye and swung his spear, chopping off Yuzuriha's hair in another. A sharp gasp escaped your lips as your hands flew up to cover your mouth, staring with big, rounded eyes.

"Don't try to negotiate, Senku," Tsukasa warned, his mouth set into a hard line. "You never buried Yuzuriha. Your best move would have been to bury Yuzuriha somewhere far away while she was petrified. That way, she'd never be taken hostage. There's no way you couldn't have thought of something that even I did. But you didn't do it. Was it for Taiju? Or for Yuzuriha? No, it was for both of them."

There was a tense moment as realization dawned upon the three of you, knowing that Tsukasa had a fair point.

Seeing he had the scientist cornered, Tsukasa went on. "You call yourself logical, but you have friends that are precious to you. I have plenty of admirers, but I have no one I'd call precious. That's why I win, Senku."

You shivered at the sight of the malicious grin painting the brunette's lips when suddenly, Yuzuriha let out forced laughter. Tsukasa's attention shifted to her as she combed her fingers through her now short hair, saying, "I actually appreciate that. Washing my hair is a pain in this world."

Then, she took everyone by surprise as she reached for Tsukasa's spear and brought the tip to her neck as she stared at Senku with glossy eyes. "Don't tell him, Senku-kun. So long as he doesn't have the recipe for the revival fluid, Tsukasa-kun can't kill you."

Your eyes watered with unshed tears, admiring her bravery despite seeing how afraid she was underneath all that.

Pressing the spear even closer, Yuzuriha went on with a kind smile. "I don't mind. But you have to survive so that you can secure everyone's future."

Senku closed his eyes, released a deep sigh and grinned through clenched teeth, having left with no choice. Releasing a deep sigh, he opened his eyes and began spilling the recipe for the revival fluid to