Winter came quietly, the way disasters always did. It wasn’t a dramatic snowfall or a sudden freeze— just a slow tightening of the air, breath fogging more easily, mornings biting harder than they should. The trees thinned. The river ran slower. The world exhaled and decided to sleep.

And Senku vanished.

Not all at once. Not in a way that caused panic immediately. At first, it was just… absence. He stopped showing up to morning meetings. Stopped correcting Chrome mid-sentence. But every time someone went looking, they’d find proof he’d been there recently— diagrams etched into stone walls, meticulous notes tied up in bundles, labeled containers of food rationed down to the gram.

Instructions. Calculations. Tiny scribbles in Senku’s sharp, impatient handwriting: Rotate the salt-drying racks every six hours. Do NOT let Magma touch the alcohol. This is not a suggestion. If the pulley freezes, apply friction manually before you do something stupid.

He was still taking care of them.

He just wasn’t there.

*Gen noticed first that it wasn’t normal. *“Okay, nope, nuh-uh, this is officially concerning,” Gen muttered, pacing in the snow-dusted clearing, scarf pulled tight around his neck. “My boyfriend does not go more than forty-eight hours without bragging about science.”

The others tried to reassure him. Senku was busy. Senku was off experimenting. Senku probably forgot to tell them something again. But Gen knew him.

Knew the way Senku always hovered near heat sources in the cold. Knew how he got quieter when he was tired. Knew how, lately, he’d been eating more than usual in the evenings and then vanishing early, leaving Gen with a half-finished conversation and a hand that slipped away too fast.

So Gen did what he always did when his mind started spiralling; He walked.

The forest was quieter now, leaves brittle underfoot, branches bare and creaking. Gen told himself he was foraging— mushrooms, roots, anything useful— but really he was just wandering, letting the movement shake loose the knot in his chest.

“Missing boyfriend, winter edition,” He sighed to the trees. “Very romantic. Ten out of ten emotional damage.”

The ground gave way beneath him without warning. Gen yelped, flailing as the world dropped out from under his feet. Snow and dirt slid with him, breath knocked clean from his lungs as he tumbled downward.. and landed hard on his side.

“Ow—! Ow, ow, ow—okay, still alive,” He groaned, blinking spots out of his vision. It was dim down here. Not pitch-black, but shadowed, the light filtering in from above just enough to illuminate packed earth walls and something smooth and dark coiled a few feet away.

Something huge.

Gen froze.

Slowly, his eyes adjusted.

Scales.

Massive, overlapping scales, dark green fading into pale cream along the underside. A body thick as a tree trunk, coiled neatly into a hollow in the earth like it belonged there.

A snake.

A very, very big snake.

“Oh no,” Gen whispered. “Nope. No thank you. I did not sign up for the ‘eaten alive by forest cryptid’ experience.” His heart slammed against his ribs as the coil shifted.

The snake moved.

A long body uncoiled slightly, muscles rippling under glossy scales, and Gen scrambled backward until his spine hit the dirt wall. “Okay, okay, listen,” He said quickly, hands raised, voice shaking despite his best efforts. “I don’t taste good. I’m mostly lies and anxiety. If you’re hungry, I can—”

The snake lifted its upper body.

And Gen’s brain short-circuited.

Because the face looking back at him— sleep-heavy eyes blinking slowly behind cracked lenses, familiar sharp cheekbones, hair a mess of pale green spikes dusted with dirt.. was Senku.

“…Senku?” Gen croaked.

The snake blinked again and looked over.

Gen screamed.

Just a little. High-pitched. Very dignified. Then he slapped a hand over his own mouth, staring. Senku, lower half a giant snake, upper half very much the same annoying genius he loved, regarded him with tired disbelief.