The Chinese Nail Murders by Robert Van Gulik

In the remote and rugged northern frontier of the ancient Chinese Empire, newly appointed magistrate Judge Dee confronts the challenges of his harsh new post in Pei-chow. Here, he encounters three perplexing cases: the mysterious theft of exquisite jewels, the vanishing of a young woman entwined in a romantic affair, and a gruesome murder marked by the discovery of a woman’s nude, decapitated body. As Dee delves deeper, he finds that these seemingly unrelated crimes are intricately connected through clues embedded in the era's popular game, the Seven Board.