Chapter 20

Chapter 20 2. Eden Lake-11

At four in the afternoon, Qi Shanyu walked into the director’s office of the pathology identification department, but didn’t see Liu Yi. In the large room, only Li Jin sat in front of a computer, bored out of his mind, staring at a spreadsheet, one hand propping his chin while the other tapped numbers into the table sporadically.

“…”

Qi Shanyu was silent for a moment, then asked lightly, “Where’s Director Liu?”

Li Jin turned his head, eyes full of grievance, but didn’t argue. He reluctantly pursed his lips and looked back at the screen. “In the pathology analysis room, at the end of the corridor.”

After saying this, he pretended to be busy, refusing to speak further, and began furiously tapping at the keyboard.

Liu Yi had spent the entire afternoon with Jiang Xiaoyuan conducting diatom tests. Considering Li Jin’s clumsy, slow approach, he didn’t bother to teach him step by step, ignoring the intern’s resentful little glances and simply sent him back to the office to continue filling out the statistics.

Naturally, Li Jin wasn’t happy with this arrangement, but Liu Yi wasn’t the type to pity or indulge someone. He wouldn’t change his mind for a few pitiful whines. To avoid truly irritating the person he secretly liked, Li Jin had no choice but to obey.

But now, seeing Qi Shanyu appear again and ask for Liu Yi immediately, Li Jin’s jealousy flared, feeling both sour and bitter. He recalled how much he had once admired that tall, handsome figure, and now it just annoyed him.

“Thank you.”

Qi Shanyu, unaware of Li Jin’s inner turmoil, simply said thanks and strode out of the office toward the pathology analysis room at the end of the corridor.

“Still nothing here either.”

Qi Shanyu entered the pathology lab just as he saw Liu Yi lift his head from a microscope, tucking a loose strand of bangs behind his ear, then marking an “X” on a sheet full of slide numbers.

“Director Liu.”

Qi Shanyu called out.

“Oh, you’re here?”

Liu Yi looked back, smiled at Qi Shanyu, and gestured to a chair beside him. Then he returned to the microscope, replacing the slide he had already examined with a new one and continued his work.

“What are you doing?”

Qi Shanyu asked.

“Oh, brewing a potion. I’ve been at it all afternoon.”

Jiang Xiaoyuan, sitting in front of the fume hood, teased, dripping a few drops of smoking hot nitric-hydrochloric acid mixture into some minced tissue at the bottom of a test tube, gently swirling it as the tissue liquefied—making it look eerily like concocting a sinister potion.

“Don’t listen to him,”

Liu Yi’s eyes stayed on the microscope eyepieces, hands working steadily. “We’re performing diatom analysis on Su Ruirui’s lung tissue.”

Since diatoms are widespread in water, many species have acid- and alkali-resistant cell walls, making them easy to isolate from tissue for examination. Smaller diatom species can even pass through alveolar capillaries with swallowed water into the bloodstream and reach other organs, often used to differentiate drowning from body disposal.

Even with only basic forensic knowledge, Qi Shanyu had heard of diatom tests and immediately understood what the mentor and student were doing.

“You just said you didn’t find diatoms?”

Qi Shanyu immediately recalled what he had heard upon entering. “Does that mean Su Ruirui wasn’t drowned?”

“Of course not.”

Hearing this, Liu Yi finally lifted his head from the microscope, giving the handsome officer in uniform a look that said, “What are you talking about?”

“In fact, it’s common not to find diatoms in the tissue of a classic, unquestionable drowning victim,”

He leaned back on the high stool, rotated halfway, facing Qi Shanyu.

“For example, the water source may have very few or no diatoms; or the species present may not survive acid or alkali, making detection difficult; or the volume of water ingested was too little, resulting in minimal diatoms entering the body, etc.”

Liu Yi counted out the possibilities on his fingers for Qi Shanyu.

“But…”

He suddenly changed tone. “Although I’ve only found one so far, I did find a diatom at the edge of Su Ruirui’s right lung tissue.”

Liu Yi turned and pulled up a recent 400x microscope photo on the computer. In the upper-right center of the image was a crescent-shaped diatom, one side convex, the other flat, with slightly rounded ends.

“This is a Crescent Bridge Diatom, common in clean freshwater rivers.”

Qi Shanyu, having learned his lesson, stayed silent, letting Liu Yi explain like a humble student seeking guidance.

“However, unfortunately…”

Liu Yi stopped teasing and pointed out the issue. “We couldn’t find this Crescent Bridge Diatom in the water sample collected from the artificial lake.”

“……”

Qi Shanyu fell silent, thinking.

He seemed to take a moment to process Liu Yi’s words, then slowly said, “You mean… the diatoms found in Su Ruirui’s body aren’t from the artificial lake?”

Seeing Liu Yi nod, he continued, “If that’s the case…”

He paused, then slowly finished, “Does that mean that although Su Ruirui did drown, the location where she actually drowned wasn’t the artificial lake?”

Liu Yi smiled at Qi Shanyu, answering with a question, “Do you think that’s possible?”

Qi Shanyu didn’t immediately nod or shake his head.

Even bold hypotheses must be based on sufficient evidence; one diatom photo alone couldn’t confirm or deny it.

“Speaking of which, I have something I want you to see.”

Qi Shanyu remembered why he came to Liu Yi, took a transparent evidence bag from his bag, and placed it in front of him.

Liu Yi pinched a corner of the bag and held it in his hand.

Through the plastic, he saw an A6 sheet of loose-leaf paper, covered with dense, irregular wrinkles, as if crumpled and flattened. Written in black pen were five words: “She was killed.” The strokes were made with a ruler to obscure the handwriting.

Liu Yi asked, “Where did this paper come from?”

“I got it yesterday at Binhai Middle School,” Qi Shanyu answered. “When I passed the teaching building, someone threw a small stone wrapped in this paper from the second-floor window, hitting near my foot. They probably didn’t want me to see them; when I chased, the person had already disappeared.”

“Heh…”

Looking at the crumpled paper, Liu Yi chuckled softly. His beautiful, crescent-shaped eyes curved with his smile.

“Seems someone does care about Su Ruirui… but as expected, they’re still just a student, afraid to risk becoming a whistleblower. The only thing they could think of was tossing a little note like cheating on an exam.”

Qi Shanyu stared at Liu Yi’s smile, finding the curve familiar—like the first time he saw him smile at a decayed, stinking severed hand without warning.

Liu Yi returned the evidence bag and asked, “Besides this, did you find anything else of value yesterday?”

“One more thing.”

Qi Shanyu snapped back to the present, pulling a USB drive from his pocket and connecting it to a lab computer.

“I checked Su Ruirui’s campus card records. Her last purchase was at 11:59 p.m. the night before her body was found.”

He opened a video. “She bought snacks at the 24-hour convenience store next to the school cafeteria, paying with her campus card. The store has surveillance cameras capturing her entering and leaving.”

From an overhead view, a girl swipes her card at the counter, puts it in her wallet, receives two large plastic bags from the clerk, and walks out of frame.

Qi Shanyu clicked the mouse, paused the video, pointing to the time in the lower right corner. “This footage proves that as of 12:02 a.m., she was alive and showed no sign of injury.”

Liu Yi hummed in acknowledgment, his eyes on the screen rather than Qi Shanyu.

“So many snacks—it’s hard to imagine a petite girl like Su Ruirui could eat all this alone. Maybe she was buying them for someone else…”

Qi Shanyu spoke, noticing Liu Yi had not responded, and glanced at him, asking, “What’s wrong? Something off?”

Liu Yi ignored him, dragging the progress bar repeatedly, looping the three-minute footage.

“Xiao Jiang!”

After the fourth viewing, Liu Yi suddenly threw down the mouse, stood abruptly, and shouted at the graduate student working at the fume hood.

“Go get all the clothes, shoes, and socks removed from Su Ruirui’s body!”

“What?”

Jiang Xiaoyuan, stunned by the sudden order, turned to Liu Yi, mouth forming a perfect “O.”

“What are you standing there for? Go now!”

Liu Yi added fiercely.

Jiang Xiaoyuan quickly dropped his half-finished work and dashed out the door like a rabbit, feet pattering away.