A hundred years ago, rumors spread that the true tomb of Marquis Wu had appeared. Heroes gathered at Sunken Dragon Mountain in the southwest, but found only an empty tomb and half a fragmentary map. Chen Zhixuan's lineage seized the map and was ambushed by the overseas School of Nine Chrysanthemums. His senior brother gave his life to protect it, leaving him with these final words: “There is a traitor in the sect.” Chen went into hiding in Peach Blossom Village.
A hundred years later, Chen Huan's parents died on a mission for the 749 Bureau. Before his grandfather passed away, he gave Chen Huan a Luban lock containing another fragment of the map. Captain Yan of the 749 Bureau invited him to join the team. They identified forgeries, solved mechanisms, and pieced together the fragments, eventually entering the true tomb, where they found a burial mound containing only the deceased's garments and the complete map.
Yan suddenly turned against them, revealing that he was the senior brother from back then, and that he had poisoned Chen's grandfather and murdered his family. The School of Nine Chrysanthemums launched a sudden attack, and the map was split into three pieces. Holding a fragment, Chen Huan gave chase. The century-old mystery was not over.
