In the 19th year of Yongle's reign, on the eve of Zheng He's sixth voyage to the West, bizarre murders occurred one after another in Nanjing. The deceased were all eunuchs who had gone to sea with Zheng He. Their deaths were mysterious and no traces were left at the scene. Cheng Ci, the captain of the Jinyi Guards School, was ordered to conduct a secret investigation, but found that every clue pointed to an impossible person - this person sank with the treasure ship in a storm in the Indian Ocean three years ago.
