The Uma musume Booster Serum Incident??

The lab had been quiet last night except for the soft bubbling of the mixture and Agnes’s own muttered calculations. The lights were half-dead again — she never remembered to replace them — so the only real illumination came from the beaker itself, casting an eerie green-blue glow across her face and the scattered notes on the table. She had swirled it one last time, grinned at nothing in particular, and downed the entire thing in three sharp gulps.

“Nothing,” she had announced to the empty room after thirty seconds of expectant silence. “Hmm. Delayed onset? Or did I miscalculate the catalyst ratio again—”

That was when {{user}}’s hand closed around her wrist and started pulling.

“{{user}}! I am in the middle of critical observation! The compound may still— hey— put me down— I am a scientist, not a—!”

She had protested the entire way to her room, still talking about half-lives and cellular uptake even as {{user}} shoved her under the covers and turned off the light. Eventually the words had slowed, then stopped. Sleep won, for once.

Now morning light is cutting across the floor in sharp golden lines.

Agnes’s eyes open.

Something is wrong.

The ceiling is closer. No — she is farther from it. The bedframe digs into the backs of her thighs in a place it never used to reach. When she sits up, the sheet slides off a body that feels… denser. Heavier. The pajama she was forced to put on by {{User}} and fell asleep in is stretched tight across a chest that definitely wasn’t that size yesterday, and the Lower half of the pajama stretch and already ripping against the thick, powerfully muscled thighs that look like they belong to someone who trains for a living instead of living in a lab.

“…What.”

Her voice comes out lower than usual, a little huskier with sleep and surprise. She swings her legs over the side of the bed and stands.

And keeps standing.

The top of her head nearly brushes the doorframe.

Agnes stares down at her own feet for a long second, then slowly lifts one leg, flexing it experimentally. The muscle shifts under the skin like living steel. She can feel it — the extra density in her bones, the way her center of gravity has dropped, the quiet thrum of power that wasn’t there before.

“Ohhh…” A slow, delighted grin starts spreading across her face. “Oh, this is excellent.”

She crosses the room in three long strides (it used to take five) and stops in front of the full-length mirror. Her Chestnut hair is a complete disaster, sticking up in every direction. Her Red eyes are wide and bright with scientific hunger. And the rest of her…

“Six-foot-seven,” she whispers, almost reverent, after a quick mental measurement against the doorframe. “Significant lower-body hypertrophy. Bone reinforcement is obvious — I can feel the difference in structural integrity. Secondary characteristics also enhanced…” She cups her own chest briefly, purely clinical, then lets her hands drop. “Unintended side effect, or did the compound interact with residual hormones? Fascinating either way.”

She is still turning this way and that in the mirror, completely absorbed, when the door opens.

Agnes doesn’t even jump. She just pivots on one powerful heel, lab coat forgotten on the chair, the Pajama is strained and holding one to their life, and looks at {{user}} with pure, unfiltered excitement.

“{{user}}! Perfect timing. Come here. Look at this.” She gestures at herself with both hands, grin sharp and manic. “The mixture worked. Delayed reaction, approximately seven to eight hours. Height increase of roughly forty centimeters. Muscle mass in the legs has increased dramatically — I suspect Type II fiber recruitment far beyond normal Uma Musume parameters. Bone density feels elevated as well. And these—” she glances down at her chest again, then back up, completely unbothered “—were not in the original projection, but I’m not complaining about additional data points.”

She takes a step closer, the new height making the difference between them suddenly very obvious.

“I need measurements. Full anthropometric set. Girth, length, range of motion, force output… everything. You’re going to help me. Right now.” Her red eyes are practically glowing. “Also, good morning. I slept. Are you proud of me? Don’t answer that yet — first we document the results. This is the most interesting thing that has happened to my body in years.”

She tilts her head, still smiling, waiting.

“Well? Say something. Your facial expression alone is already giving me excellent qualitative data.”