Prologue

*(The following is entirely fictional: as if a cute girl would ever study for academic competitions with you.)*

Inside the main library of a top university in southwest Shanghai—one of the ten schools claiming to be ranked third in the country—I, a freshman in the life sciences class, opened the materials for the new week's literature seminar under the warm 3:00 PM sunlight. Why do I have to endure this kind of torture when I've only just started college?

Staring at the jargon-filled English paper on my screen, "MeCP2 links heterochromatin condensates and neuro-developmental disease...", I felt my scalp go numb. Those complex words and obscure sentences felt like impassable chasms standing between me and knowledge. To make sense of it all, I dived headfirst into an ocean of reference materials, searching desperately for explanations and guides across various academic websites and databases. By the time I finally looked up from the pile of papers, I was startled to find that twilight had already fallen outside the window, and I had somehow missed dinner.

The prolonged, intense mental focus left me utterly exhausted. Unable to hold myself up any longer, I let my head drop heavily onto the desk in front of my laptop. Right then, fragments of hazy memories surged from the depths of my mind like a rising tide. Under this same 3:00 PM sunlight, a figure had once reached out to me with a smile as bright as spring blossoms, her clear voice saying, "Hey, join the paper study club!" I tried desperately to see her face clearly, but before my eyes could focus, the smile dissolved like evaporating mist, leaving me behind with a hollow sense of loss.

The library's closing bell rang urgently. I hurriedly packed my things and rushed toward the dormitory to the rhythm of the chimes. The ginkgo leaves rustled under my feet. Each leaf felt like a bookmark of time, turning back the pages of the past. In a daze, I seemed to return to the main avenue of Jianglin High School, my palm seemingly feeling that familiar warmth once again. She leaned down to pick up a few golden ginkgo leaves, gently placing one in my palm. With a lively spark in her eyes, she said, "Ginkgos are so lonely—Division Gymnospermae, Class Ginkgopsida, Order Ginkgoales, Family Ginkgoaceae, Genus Ginkgo, Species *Ginkgo biloba*..." Like two little explorers discovering the world, we eagerly debated why the leaves on the left side of the road turned yellow earlier—whether the school building blocked the sunlight, or if the moisture from the campus pond affected the humidity.

Later, I finally had my first experience in a university laboratory. When I put on the white lab coat—that symbol of scientific exploration—for the first time, walking in with nervous anticipation while clutching my lab notebook, I saw the reagent bottles and Bunsen burners neatly arranged on the benches. They reflected a cold, hard light, as if declaring to me the rigor and mystery of science. I took a deep breath and slowly lifted the burner. Just then, a familiar figure appeared on the other side of the lab bench. It was her. The braid resting on her right shoulder bounced playfully with her movements. She smiled and said, "This is my secret base! And now... it's our secret base!" In my mind's eye, I saw her again, winking mischievously from behind the small door of the Jianglin High School basement. In the dim room, dust motes danced in the faint light like dreamlike stardust.

Yet, time flows ruthlessly. Now, she has vanished, leaving behind nothing but these beautiful memories. During countless quiet, early hours of the morning when I was working alone in the lab, her figure would always appear out of nowhere. She lay quietly on the lab bench, her pink hair cascading like a waterfall, her lips a mysterious shade of ultramarine. This nightmare-like vision haunted me time and again in the dead of night, leaving me with no escape from my longing for her.

Her name was Zero Aldehyde—a name forever vivid in my memory. A past I could never let go, all because of her, and etched deep into my soul because of her.