Doctor In The House (Dr. STONE Fanfiction)

Fire the Smoke Signal

With his signature chuckle, Senku placed a bundle of charcoal on the ground. "The three main raw materials for the gunpowder have been gathered." he said.

"You've gathered them all?" asked Taiju excitedly.

"Next, we just need to mix them together." added the green-haired man, whose grin widened with glee. "Now, here comes the fun gunpowder-mixing time."

A sweatdrop formed on the back of Rikona's head, followed by a mushroom sigh as she thought, 'He kind of reminds me of my Physiology professor when he got excited about experiments. I feel like we've been roped into his surprise class.'

As if on cue, the setting suddenly resembled that of a cooking class; or rather, Senku's kitchen began. "The first ingredient for gunpowder is the limitless supply of sulphur from the hot spring." he began. Yuzuriha poured a bucket of sulphur into a large sack before Rikona added the charcoal one by one. "Second, charcoal. We can easily get this by burning some wood. And third, the last and the most difficult one, potassium nitrate. It's very time-consuming to make this." At that moment, he held up a bag of white powder. "We've prepared potassium nitrate in advance."

"Ooh!" exclaimed Taiju, who then had a look of puzzlement as he glanced up to think hard. "Nitrate? I think I've heard that before. It's nitric acid! The Miracle Fluid! Did you take it from the cave?"

"Not every day a musclebrain like you can get the right answer." remarked his friend. "Ten billion percent points for you." After adding potassium nitrate into the mixture, he took a stick and started stirring as he continued explaining. "Mix potassium nitrate, sulphur, and charcoal. With a pinch of sugar, it'll increase its power." But instead of granulated sugar, he poured some liquid into the mixture from a bottle in their inventory. "By the way, this is glucose extracted from grapes." When he was done with the mixing, he tightly closed the sack before raising a log up high, aiming at the sack. "Lastly, pound it hard until it forms a mass."

At that instance, Taiju lifted up a boulder. "Did you say pound it hard?!" he clarified. "Leave the hard work to me!" The very sight of his strength, coupled with his enthusiasm, caught his friends off guard. Rikona, on the other hand, stood at the side with an owlish blink.

Worried that something bad would happen, Yuzuriha quickly stepped in. "That's not a good idea." she advised. "Given your physical strength, won't it produce sparks and cause an explosion like flint?"

"No, hitting stones against one another will not produce sparks." reassured Senku.

"Really?" she asked, both surprised and confused.

Taiju went forward and started pounding the sack with the boulder. Just like Senku said, there was no reaction caused by the impact. "It's true." he noted.

"Flint isn't just made of stones." explained the green-haired man. "Without iron, it will not produce sparks."

"Senku." called Rikona. "What is flint made of?"

Now, this was odd. Why would someone like her ask him a question he thought she'd have the answer to? But either way, he answered, "Hot springs, volcanoes, iron pyrite-" He suddenly paused mid-sentence. Wait, did he just mentioned- "Iron pyrite?!"

So that was why she was standing so far away.

Taiju slammed the boulder onto the sack once more before removing it, only to reveal that the material had torn off and numerous sparks began igniting inside. The trio stared at it with blank expressions before Rikona stepped it and attempted to drag everyone away. But they were still mere seconds too late, as the explosion went off and the impact blew them away. As black soot emitted into the air, Senku got back on his feet and observed.