Constant Variable (Senku x Reader)

13: Masked Warrior

"Welcome back!" Suika greeted loudly as she ran up towards all of you, leaping with joy and relief at the group's safe return.

"We made it past the biggest hurdle!" Chrome cheered with a fist pump while the rest of you wore wide grins on your faces, all carrying large jars of sulfuric acid. "We got sulfuric acid!"

Tears gathered in the corners of Kohaku's eyes as her lips stretched into a hopeful smile upon hearing those words. "Then, at last, we can make the drug to save Ruri-nee?"

"Have some patience," Chrome replied, his voice falling flat as he stared at the blonde with furrowed brows. "Didn't you see that crazy roadmap to the cure-all drug?

"That incredibly long one?" Kohaku asked in a dreadful tone, her shoulders dropping at the thought of it.

Chuckling, Senku glanced over his shoulder at the pair, the corners of his mouth lifting into a confident smirk. "It's not bad. We have just about everything we need now."

Everyone's faces lit up at the good news, bright smiles breaking out on their faces. Seeing their enthusiasm, you let out an amused giggle and said, "We have all the necessary materials. Now, it's just a matter of lighting up all the dark spots on the roadmap, one by one."

"Let's plow through it today." The green-haired scientist declared as he entered the laboratory, grabbing a handful of test tubes and glass beakers, red eyes blazing with mad glee. "Time for mad chemical cooking! It's gonna be exhilarating!"

The rest of you let out loud cheers of eagerness and soon, everyone got done to work.

"First, we boil the sulfuric acid we got, and add a pinch of salt. "Senku explained as everyone gathered around the pot of boiling sulfuric acid.

"There's a weird glass sculpture with a stick in the middle," Suika noted, her watermelon-mask head tilted to the side in curiosity.

Meanwhile, Kaseki popped up out of nowhere with tears streaming down his cheeks while complaining, "How dare you make me make such a complicated thing?! I don't know what you're using it for, but you've gone and made me all excited!"

"It's a water dripping machine," Senku replied, sweatdropping at the old man's dramatic response.

Chrome stared at the weird contraption with furrowed brows, asking, "Are we catching the gas that's coming out of the sulfuric acid and salt mixture as it drips?"

(E/C) eyes lit up with realization when it dawned upon you what your friend was making due to how familiar the setup looked. Turning to Senku with a beaming smile, you asked, "Oh! You're making hydrochloric acid, am I?"

"Good job, (Name). You got that right," Senku returned your grin with a small one of his own and you preened at the praise.

"Hydrochloric acid?" Kohaku asked in a confused tone.

"It's a somewhat dangerous chemical." The scientist answered, red eyes glinting with mischief. "Get in your eyes, and you'll go blind."

Upon hearing that, Suika's face turned pale in fear, and it earned the teen a light scolding from you when you noticed the frightened look on her face.

"Senku, couldn't you have phrased that in a nicer way?" You frowned at your friend while placing a comforting hand on the top of the young's girl mask. "You're scaring Suika."

Instead of feeling sorry, Senku simply ignored you and moved onto the next step. "Next, the sinters from the sulfuric acid spring, which people love taking home from hot springs. Boil this stuff, throw it into the hydrochloric acid we just made, and we have chlorosulfuric acid.