He had a late-night snack, returned to the dormitory, and went through the materials he photocopied today once more. He read until it was past ten at night, when he really couldn’t hold on anymore, so he packed up the materials and switched off the light.

Lying on the bed, he closed his eyes, but his mind was still filled with those words. He recalled Yang Ping’s words: don’t preconceive, let the evidence speak. He remembered the line in Professor Zhou’s experimental record book, "recommend termination of further development of this compound," was it a scientist’s judgment, or a scientist’s concealment?

Zhaxi turned over, forcing himself not to think about those things anymore.

On Monday morning at six-thirty, Zhaxi was already sitting in the small meeting room at the Institute. He again reviewed the material he photocopied from the archives yesterday, especially the meeting minutes and Professor Zhou’s toxicology experiment records. He noticed a detail: in Professor Zhou’s experimental records, the percutaneous toxicity experimental data was described very meticulously, with every rat’s dosage, reaction time, and time of death documented. But on the bottom right of one page, there was a small pencil mark, reading "repeat experiment 3 times, results consistent." This mark was very faint, hardly noticeable without a close look.

Why write such a line in the bottom right corner? Was it to prove something?

At exactly seven, Yang Ping pushed the door open, carrying two cups of tea, placing one in front of Zhaxi. Zhaxi took it; the tea was still hot. "Where is Officer Yu and the others?" Zhaxi asked.

"Planning to go directly to Professor Fang’s home; we shouldn’t bother an eighty-one-year-old man too much." Yang Ping sat down, opened the materials Zhaxi had organized, "Professor Fang’s full name is Fang Mingyuan, one of the leaders of the project back then, and also Professor Zhou’s senior. Ever since retiring, he has lived in Nandu, reportedly in good health with a clear mind. When Officer Yu contacted him last night, he was informed of Professor Zhou’s death, remained silent for a long time, then said one sentence, ’What had to come came.’"

Zhaxi was taken aback: "What had to come came? What does that mean?"

Yang Ping shook his head: "Don’t know, that’s why we’re going to ask him today."

At seven-thirty, Officer Yu’s car arrived at the hospital entrance. This time, only Officer Yu was present; Xiao He stayed in the laboratory dealing with the detection results of those books.

"Let Zhaxi go with you, contact me anytime if you need my help, I have some matters today and actually, you guys don’t need me that much." Yang Ping told Officer Yu.

Zhaxi got into Officer Yu’s car; Officer Yu handed Zhaxi a document: "Found some more things last night. Director Zhang and Dr. Yuan’s opinion is for me to maintain close contact with you, since this type of case has already exceeded our knowledge range and can easily stray off track. It’s not a matter of experience but of cognition. We’ve also consulted a well-known chemist domestically, but although he is proficient in chemistry, he lacks logical organization of the whole matter. He also suggests consulting a toxin expert doctor, as doctors excel at using symptoms as clues to find underlying reasons and at organizing various elements together."

Zhaxi took a look; the document was more background information about Professor Zhou’s project from thirty years ago. Officer Yu’s voice came from the front seat: "The A-8 project was terminated in 1992, and the project team disbanded. But according to the information we’ve found, considerable funding had been invested in the project before its termination, even a small pilot production line was built. The Chemical Department had high hopes for the project, hoping it could become a domestic product replacing imported pesticides at the time."

He paused, then said: "After the project termination, someone was held accountable. A deputy section chief from the Chemical Department was therefore relocated from his position, Professor Fang from the Chemistry Department of Nandu University also received a disciplinary report. But Professor Zhou was not held accountable because he was the main technical staff of the project, and he insisted his toxicity data was accurate."

Zhaxi asked: "What happened afterward?"

Officer Yu replied: "There’s no afterward; the project was thoroughly sealed, all information archived, and the A-8 compound was never researched again. Until now."

Zhaxi was silent for a while, then asked: "Was the disciplinary report received by Professor Fang back then serious?"

Officer Yu thought about it and said: "A disciplinary report was considered relatively light at the time. But Professor Fang is a person who values reputation highly, and the matter hit him hard. He never applied for major projects afterward, just taught courses and guided students in the department, and retired when the time came."

Zhaxi nodded and didn’t say more.

Professor Fang Mingyuan lived in a community in the Nandu Old City District, not far from Nandu University. The community was quiet, well-planned, with not very tall buildings, six-story buildings with beige walls, seeming to be buildings from the late 1990s. Officer Yu parked the car downstairs, and the four of them went up to the third floor. Professor Fang’s son was already waiting at the door, around forty, wearing glasses, appearing very refined.

"Officer Yu, my father is waiting for you in the study." He said in a low voice, "He didn’t sleep well after hearing about Professor Zhou’s matter."

The study was not large but neatly organized. Two walls were fully lined with bookshelves, packed with books. By the window stood a desk with an open old album spread on it. Fang Mingyuan sat at the desk, eighty-one years old, hair completely white yet still in good spirits, with bright eyes. He was wearing a gray sweater, holding a steel pen, fingers spotted with age spots but very steady.

Seeing Yang Ping and the others come in, Professor Fang slowly stood up and extended his hand: "Thank you for your hard work!" His voice was somewhat hoarse but articulate.