At nine in the evening, Bingxin began examining the bottle of wine. There were three groups of fingerprints on the bottle, one belonging to Mr. Huang, the other belonging to me–from serving the wine during our lunch–and the other was unknown. It probably belonged to the man who gifted the wine.

The composition of the glass used to create the wine bottle contained silicon sulfide. Bingxin googled it and found that it was probably French-made. The original bottle may have been filled with imported red wine.

As for the ingredients contained in the wine, Bingxin could only identify tannin. The rest couldn’t be identified without comparative samples. After all, there were more than twenty thousand known toxic substances in the world, and...