After a bet on a fight is made and an attempted assassination is thwarted, a man recently returned to town finds himself on the trail of a skilled killer leaving only a Mark of Blood on his victims.
Liang Meilan sneaked into Zhou Zhigang's home and abducted his daughter Liang Meifen, pretending to be her and waiting for an opportunity to regain the family heirloom's Night Pearl. It turns out that Meifen and Meilan are twin sisters. Lan's mother was insulted by Zhigang eighteen years ago, and Zhigang even killed her husband and took away his family property. After many risks, Meilan finally succeeded in seizing the treasure, and Detective Li Haiming also found out everything.