I asked Xiaozhou about the results of the lab testing, and he told me that the capsule found in the victim’s stomach contained Cedilanid, which was a common drug used to treat heart disease.

“A heart medicine, huh?” I mumbled. “Any other discovery?”

Xiaozhou replied that the drug sample I took from the victim’s skin was an unknown chemical, while the substance that was injected into the victim’s body four hours ago was an unknown biological enzyme. The effects of these two substances could offset each other, which was to say that the victim had both the poison and the antidote injected into his body!

“I get it now!” I exclaimed. “The murderer controlled Chen Da by injecting poison into his body then forced him to act a certain way by promising to give him the antidote!”

Xiaozhou nodded in agreement, then added, “The dose of antidote found in the victim’s body is too small, though. It wouldn’t be enough to completely neutralize the po...