Worried for Mortimer who was kidnapped by General Xi-Li's men, Captain Blake, accompanied by Chinese nationalist agent Ylang Ti, starts looking for his friend. Using the clues that Mortimer had the intelligence to sow on his way, they gradually go back the track that should lead them to him. For their part, Mortimer and Han-Dié, a nationalist archaeologist who betrayed his government to sell historical documents to General Xi-Li, are forcibly taken to the warlord's den. Mortimer takes advantage of this trip to learn more about the documents that will prove to Xi-Li that he is indeed the descendant and heir of Shi-Huangdi, the first emperor of China.... whose legend says he was taken to the end of his life in the Valley of Immortals.