In Theory [Senku x Reader]

"The important thing is not to stop questioning. Curiosity has its own reason for existing." – Albert Einstein.

You were going to freeze your fingers off.

No, literally.

Your hands were so numb they might as well have been detached from your body—stiff, unresponsive, and useless against the relentless winter air. At this point, if you weren't careful, they might just snap clean off like brittle twigs.

Actually, scratch that. You might fall to your death first. Hard to say which was worse. Both were equally unpleasant in the grand scheme of things.

You exhaled sharply, willing yourself to keep climbing—one agonizing step at a time. The bitter cold gnawed at your bones, the wind lashing against your face as your breath came in shallow bursts. Every movement was a calculated effort, a battle against both gravity and frostbite. But eventually—finally—your feet met solid ground.

With a shaky exhale, you collapsed onto the edge of the sky-tree, the icy New Year's wind slashing against your face.

A warm bowl of ramen sounded like pure heaven right about now.

But instead of savoring one while counting down to midnight, you were stranded in what you could approximate was somewhere 2,080 feet in the air, shivering so hard your teeth rattled. The sharp tang of iron filled your nose—your body protesting the climb in the form of split knuckles and chapped lips.

You gritted your teeth against the shivers, forcing yourself upright.

"I'm going to freeze to death..."

"C'mon! You got this! If Senku made it up here, then you definitely can too!"

Taiju's face popped into view, bright with his usual boundless energy—like this was just another casual morning jog. You groaned, barely mustering the energy to glare at him, before turning your gaze toward Senku.

Despite always lagging behind in physical tasks, he was already setting up the contraption he'd dragged all the way up here, his focus unwavering.

Science, apparently, was a stronger driving force than basic human survival instincts.

Not wanting to be outdone by the radish of the group, you pushed yourself to your feet and trudged over to where the two sat, each step heavy with exhaustion. Your breath came in sharp, visible puffs, but you ignored the burn in your lungs as your gaze landed on the bags Senku had been so insistent on carrying since the start of this definitely-not-dangerous-or-crazy plan.

With a skeptical glance, you knelt down, eyeing the bag as if it had done you great wrongs. Then, with a curious poke, you asked, "Alright, what exactly did you bring that required us to climb all the way up here?"

Taiju, who had just made his way over, perked up immediately, practically vibrating with excitement. "Oh! I know! You're launching your new model rocket from up here!"

"Wrong."

Well, that was fast.

Senku's grin widened—never a good sign. That look meant one thing: whatever he was about to unveil was not only science-related but also, without question, absolute madness. You had already doubted the rocket theory, but if it wasn't a rocket, then what?

Also... were the three of you even allowed to be up here?

Before you could voice that concern, Senku—his ridiculous hair somehow defying both gravity and the cutting winds—unzipped the bags. A series of heavy metal poles and an assortment of instruments clattered onto the icy surface. The dim glow of the city lights below barely illuminated the setup, but even in the low light, it was obvious: