“If the killer merely passed through the corridor and happened to see you going through the papers, how — through a door — would they know that what you were looking for had anything to do with Yu Xiaozhen?” Shi Ting’s gaze was cutting. “Only someone close to you would know you were investigating Yu Xiaozhen.”

Yan Qing’s composure slipped. She almost glared at him. “Shi Ting!”

It was the first time she had called him by his full name — both given name and surname — and she used it purely to express her displeasure in that moment.

Yet when Shi Ting heard those two syllables, his gaze softened visibly. There was even a trace of indulgence in it — and something like helpless resignation.

He slowly crouched down in front of her, lowering his gaze to try to be level with hers. A cool, crisp air clung to the man, yet it wasn’t aggressive or pressing — he was making a deliberate effort to ease his manner, as if afraid to provoke her again.

“Yan Qing, you already know quite clearly — the person who went through those papers was very likely Jing Lan. She slipped back into the records room after you left last night and worked through the rest of the papers. The papers might not actually matter much to the case, but there’s a saying: a guilty conscience makes a thief jumpy.” Before Yan Qing could speak, he continued, “Of course, without any evidence to prove it, everything I’ve just said is speculation. It’s entirely possible that Jing Lan is innocent.”

“When the gatekeeper opened the door, the lock was undamaged. After I noticed the papers had been moved, I checked the doors and windows — the bolt was fastened from the inside, and there were no marks of anyone stepping on the window ledge.” Yan Qing gradually steadied herself. “The killer must have had a key. She entered through the main door.”

“The killer not only has the key to Classroom 104 — she even has the key to the records room. I suspect that whoever holds the gatekeeper Jiuwan’s key ring, she has made a copy of every single one.” Shi Ting looked into her bright, clear eyes. “Think carefully — what is Jing Lan’s relationship with the gatekeeper Jiuwan?”

Though she knew he was still suspicious of Jing Lan, Yan Qing was a professional forensic investigator. After a brief moment of lost control, she steadied her emotions again.

Her second uncle had told her: every object surrounding a case is potential evidence, and every person is a potential suspect. They may not be the killer — but they must still be considered.

If she believed it wasn’t Jing Lan, what she needed to do was help clear Jing Lan of suspicion.

“From what I know, Jiuwan once suffered an epileptic seizure in the gatehouse, and it was Jing Lan who found him and administered first aid on the spot. She essentially saved his life. There’s a stove in the gatehouse, and Jiuwan keeps hot water heating on it. Jing Lan can go in and use the hot water whenever she likes.” The school’s living conditions were quite basic — no underfloor heating in winter, no provision of hot water. A warm cup in winter was considered a small luxury.

“Jing Lan is close to Jiuwan and can come and go from the gatehouse freely. While Jiuwan is sound asleep, slipping the keys away and having copies made would not be difficult.” Shi Ting said, “Before I came here, Zheng Yun sent back a report from Poyao. The first and third squadrons have thrown their full force into searching the area, and they’ve finally found something. A local resident, after seeing Yu Xiaozhen’s photograph, confirmed that Yu Xiaozhen did indeed live in Poyao a year ago — and was even this resident’s neighbor. She remembered clearly that Yu Xiaozhen had a younger sister and a father who was bedridden with illness. Her father was too ill to get around, and her sister also never left the home. This neighbor had never once seen the sister’s face clearly — only caught a fleeting glimpse through a window.”

Yan Qing’s brow furrowed delicately. She opened her mouth, but said nothing.

“This neighbor also said that one year ago, the family disappeared overnight. The next morning when she got up, the place was empty — not a soul left.”

—