As we were on stakeout, I called the Director-General and gave him a brief summary of the current progress. After hearing my report, he said, “If the evidence is conclusive, the judiciary can issue an arrest warrant.”

“Can a person be convicted for murder if they use a curse to kill the victim?”

After a moment of silence, Director-General Cheng replied, “That would be difficult. Modern law is based on scientific principles. But as I said, special circumstances may be treated specially. If you have solid proof that the curse can be used to murder people, then leave the judicial process that follows to me.”

“I’ve been a police officer for nearly forty years,” he added. “I’ve been exposed to hundreds of cases. A number of them involved factors that were difficult to explain with common sense or scientific principles alone. Personally, I believe your judgment about...