Chapter 144: The Real Culprit

We stepped outside and found Cheng Yahui collapsed on the ground, his body curled up like a giant shrimp. He wasn't unconscious, but he kept groaning softly.

Huang Xiaotao kicked him lightly and said, "Get up, huh? Trying to scam a cop now?"

I waved her off. "Wait, something's wrong. I think he's been poisoned."

I pried his eyelids open to check. His eyes were bloodshot, pupils constricted—classic signs of poisoning. This was strange. He'd been under police watch since morning. Who could have poisoned him? And how?

I called Wang Dali to fetch some soapy water immediately. We needed to induce vomiting, fast.

Cheng Yahui grabbed my wrist tightly, his voice cracking, "My medicine… it's in the interrogation room…"

Huang Xiaotao sent an officer to check. Sure enough, the cop came back with a bottle of medicine found under the interrogation room table. The label said it was a sedative. But no one dared to give it to him—what if it caused more harm? Inducing vomiting was the safest bet.

Seeing the medicine, Cheng Yahui went frantic, begging, "Give it to me… or I'll be in unbearable pain…"

Huang Xiaotao said firmly, "No way. We have to test this first."

...

...

"Quick… give it to me!" His face twisted in agony.

Suddenly, it clicked. I snatched a pill and shoved it into his mouth. Huang Xiaotao shouted, "Song Yang, what are you doing?"

I said, "It's the antidote."

Within a minute of taking the pill, Cheng Yahui recovered: "Sorry, everyone. I have a chronic nerve pain condition. Without this medicine, the pain flares up."

I asked, "Nerve pain that severe? Who prescribed it?"

Cheng Yahui answered, "I'm a doctor. Of course, I prescribed it myself."

I frowned. "You're a gynecologist. You know about this?"

He chuckled, "I'm a PhD in medicine. This symptom is easy for me to recognize."

I said, "Please wait a moment. We still need to run tests."

Though reluctant, he had no choice. We took him back to the station and asked for a urine sample. Naturally, the task fell to Sun Bingxin. Half an hour later, she emerged from the lab.

"The components of the medicine can't be identified—it seems custom-made. But the urine contains atropine-like poison."

I mused, "Yin-Yang combination poison."

Huang Xiaotao looked puzzled. "What's that?"

I explained, "It's a poisoning method recorded by my ancestors. Two drugs are hidden in two separate things. Taking either alone is harmless, but together, they cause poisoning. Or reversed: poison in one dish, antidote in another. When served together, they quietly kill the target during a meal."

Sun Bingxin nodded, "That aligns with toxicology principles—synergistic or antagonistic drug interactions. Sometimes two drugs combine to form a toxin, or one neutralizes the other."

I said, "If Cheng Yahui hadn't made a scene, we might never have uncovered this. The poison was administered by the killer—someone close to him."

Everyone's thoughts turned to one person: Qu Tingting.

We brought Cheng Yahui back to the interrogation room. No matter how we questioned him, he insisted he prescribed the medicine himself. I asked, "Who usually gets your medicine for you?"

Without hesitation, he answered, "Nurse Qu."

I asked sternly, "What's her education level?"

He said, "Some kind of diploma? I'm not sure. Besides work, I don't talk to her."

Huang Xiaotao waved him off. After Cheng Yahui left, the room fell silent. We had overlooked a huge blind spot—Qu Tingting was the real culprit. Her motive had to be jealousy.

Huang Xiaotao called out, "What are we waiting for? Arrest her now!"

We rushed to the affiliated hospital, but Qu Tingting wasn't there. The head nurse's phone number was unreachable. Huang Xiaotao sighed, "Damn it. She saw Cheng Yahui was arrested and fled."

I said, "Check the gynecology outpatient clinic."

The room was neat and tidy. On the desk lay a stack of white papers. Huang Xiaotao sighed, "Nothing here."

"Wait!" I sat down and scribbled on a sheet with a pencil. Slowly, words appeared:

"Dr. Cheng, I'm leaving. Probably won't be back for a long time. I left your medicine on the desk—remember to take it. It won't last long, but if you come to see me, I'll tell you the formula. Also, there's something I need to tell you..."

The note suddenly stopped, torn halfway through.

Huang Xiaotao said, "She won't be back for a long time... Could she be turning herself in?"

Suddenly, I blurted, "What's the difference in sentencing for killing four people versus five?"

"Both are death penalty!" Huang Xiaotao exclaimed. "You mean she's going after the florist?"

I said, "Highly likely. Let's hurry. Maybe we can save a life."

Huang Xiaotao called officers on standby. We got the florist's address from Cheng Yahui and rushed over. As soon as we entered, a poised woman asked, "Looking to buy flowers?"

Wang Dali stared at her, his eyes fixed.

Huang Xiaotao showed her badge and explained briefly. At first, the woman denied any involvement with Cheng Yahui, claiming she was married. But when she heard she might be targeted for murder, her story changed—she admitted to having a relationship with him.

Huang Xiaotao instructed other officers to set up surveillance around the shop. We stayed inside, mainly to bait the trap.

The wait was boring. Sun Bingxin studied the flowers and said, "Brother Song Yang, I really like this white rose. Could you buy one for me?"

Huang Xiaotao scolded, "Hey! What are you doing here?"

Sun Bingxin stuck out her tongue playfully. "I'm not serious. Just chatting."

Huang Xiaotao said to me, "Song Yang, my birthday's next month. I don't want you to spend much—just get me a red rose."

Sun Bingxin gasped, "But you're partners! Red roses are for couples. Don't you know that?"

Huang Xiaotao snorted, "So what? I just like red roses. I want him to buy one for me!"

"You… abuse of power! I'll tell my dad!"

"Always calling parents. You're such a kid!"

They glared at each other, and I felt awkward in the middle. I said, "How about I buy one for each of you?"

They both said in unison, "No!"

The florist chuckled, "Are you really cops? Or just here to tell jokes?"

Huang Xiaotao said, "Don't cops have private lives? By the way, Amy, your private life seems quite messy."

The florist scoffed, "I know what kind of man he is. He's just a bus to me—who'd ever fall for that? My marriage's a mess. I just need a fling to pass time."

She was quite open-minded after her experience. Wang Dali muttered, "Man, why can't I meet someone like that?"

The florist batted her eyelashes. "Young man, you're not bad looking. Come chat with me sometime."

Wang Dali got excited and nodded eagerly.

I immediately coughed loudly and shot him a sharp look. As a college student, he shouldn't be so shameless.

By noon, the florist said, "You guys have been working hard. Let me order some takeout for everyone."

Wang Dali said, "Great idea!"

Huang Xiaotao rolled her eyes. "Thanks, but we're on duty."

She ordered some food. Just as she was about to eat, I shouted, "Hold on, let's check it first!"

The florist smiled wryly. "You're overreacting. I eat this takeout every day. If there was poison, the place would have been shut down."

I said, "Today's a special situation. We have to test it."

We took samples of each dish. Sun Bingxin opened her kit and began testing. Afterward, she said, "No poison detected."

The florist sighed, "Well, the food's cold now."

She ate quickly and was about to light a cigarette.

I said, "Wait, one more test."

The florist frowned, "Are you done yet?"