Chapter 137: The Botulinum Murder Case

"How was she poisoned?" I asked.

"There's a puncture mark on her thigh. Looks like she injected herself with something. Could it be suicide?" Sun Bingxin suggested.

"Never jump to conclusions," I replied. "That's the number one rule in forensic work."

She stared at me and smiled.

"What?" I asked.

"You've become so mature, Brother Songyang," she said with admiration. "Even more composed than a seasoned forensic doctor. I still remember when you used to tell me all those stories about Judge Song Ci cracking cases. I knew you'd grow up to be someone remarkable."

I laughed awkwardly. "I've just seen too much, that's all."

"So what now?" she asked. "Should we wait for the police to take the body for autopsy and lab testing?"

"That's the standard procedure," I said. "But a coroner can perform a full examination on-site. Let me show you what the Song family's techniques are really capable of."

I pulled out the Bone Listener—a wooden tool passed down through generations of coroners—and listened to the victim's internal organs. Everything sounded relatively normal. Then I rested her head on the Yin-Yang Pillow and tapped around the inside of her skull.

What I heard made my heart skip a beat—there was liquid inside.

Thinking I might have misheard, I knocked again. Same result.

"The internal organs are intact," I announced. "But there's fluid inside her skull."

"Wait, what?" Wang Dali blurted out. "Did her brain flood?"

I shot him a glare, and he lowered his head. Sun Bingxin was shocked. "You could tell that just by tapping on a wooden block?"

"I'll explain later," I said. "But my conclusion is this: a neurotoxin dissolved her brain."

"Her brain and her muscles?" Sun Bingxin muttered, clearly baffled.

Honestly, even I had no idea what kind of poison could do both. I remembered something from The Chronicles of the Corpse Whisperer—a substance called Waxman's Toxin, rumored to melt flesh until the body resembled a wax figure. But this didn't quite fit.

The victim was naked except for a pair of underwear. There were no signs of a struggle or sexual assault. Without sunlight, I couldn't use my Forensic Umbrella, so I dusted her skin with seagrass ash. As expected, only her own fingerprints remained.

In the break room, I found her clothes on a small bed. Inside the pockets were two ID cards—one student ID and one meal pass. Her name was Xiaoli, the same work-study girl the cook had mentioned.

I used Ghost-Eye Vision to examine the area more carefully. Something was under the bed. I pulled it out—an empty injection vial and a used syringe. There were no labels.

"Should we send this for lab analysis?" Sun Bingxin asked.

"That would help," I said, "but we should also try some basic deduction."

She examined the puncture site and traced the injection angle. "She likely injected herself. So… suicide?"

"Let's think this through," I said. "This would've been a painful way to die. Why not choose a faster, less agonizing poison? Also, look at her posture—she clearly struggled to reach the door before collapsing. And the buttons on her shirt were ripped off—she took off her clothes in a panic. Why?"

"Maybe she was burning up from the inside?" Sun Bingxin guessed.

I picked up her shirt and smelled it. No sign of sweat or heat-induced body odor. "Doesn't check out."

"Let me see the vial," Sun Bingxin said.

She held it up to the light. "There's some black residue inside."

That triggered a hunch. I handed her the ID. "What do you think—was she pretty?"

"She was," Sun Bingxin said, puzzled. "Why are you asking that now?"

"I think I know what the toxin was," I said. "Think of a four-syllable poison."

Sun Bingxin started guessing: "Dinitrophenol? No, symptoms don't match. Creatine kinase? That doesn't dissolve the brain…"

She rattled off more than ten poisons in under a minute—some I hadn't even heard of. Her toxicology knowledge was impressive.

Wang Dali suddenly interjected, "Could it be that legendary one—'kills on contact'?"

I rolled my eyes. "She didn't even bleed."

Then Sun Bingxin gasped. "Wait! You asked if she was pretty… oh! She had cosmetic surgery, didn't she? It was botulinum toxin!"

"Bingo," I said.

"What's botulinum toxin?" Wang Dali asked, confused.

"It's a cosmetic injection," Sun Bingxin explained. "A muscle relaxant, used to reshape the face or slim down body parts."

Botulinum toxin dissolves proteins, which is why it's widely used in cosmetic procedures. But most people don't know it's also one of the most lethal toxins known to humanity. Militaries have even weaponized it—hence its prohibition under the Geneva Convention.

Just one milligram of botulinum toxin can kill 200 million mice. Cosmetic clinics only use minuscule doses. Even then, celebrity cases of facial paralysis and nerve damage are not unheard of.

This toxin is anaerobic—it dies quickly when exposed to air. But when Sun Bingxin mentioned the black residue in the vial, I knew what it was.

Xiaoli had likely bought botulinum online to slim her legs. After injecting it, she noticed her muscles deteriorating rapidly. Panicking, she tore off her clothes and tried to seek help. But the toxin reached her brain too fast. She collapsed at the door and never got back up.

The botulinum kept replicating inside her, dissolving her muscles and brain in less than 12 hours. By the time we found her, she was barely human—more like a zombie.

"She probably couldn't afford a professional procedure," Sun Bingxin said sadly. "So she bought a cheap version online and paid for it with her life. What a tragedy… But it was still just an accident, right?"

"No," I said firmly. "It was murder."

"Murder?" she exclaimed in shock.

"Just look at this vial. You can see the toxin with the naked eye. No legitimate seller would ever sell something this dangerous. It was either deliberately tampered with… or a malicious counterfeit. Either way, someone wanted her dead."

Sun Bingxin nodded slowly. "You're right. So what do we do now?"

"Secure the crime scene and wait for the police," I said, then glanced at the unconscious chef. "Dali, wake him up. I've got questions for him."