In the Ming Dynasty, two Shanxi generals, Qu Wei and Du Gu Jiu, are murdered while escorting treasures to Beijing, leaving their deaths shrouded in mystery. When the generals' legendary sword "Meng Lao" appears in the hands of Jiang Hu thief Lu Kun (Ding Yi Sen), he seeks help from detective Mu Bin (Zhong Zheng) to prove his innocence. With only three days to solve the case, Mu Bin investigates the complex web of clues, uncovering darker forces behind the murders. Racing against time, Mu Bin must use all his skills to uncover the truth and prevent an innocent man from suffering an undeserved fate. This is a 2019 South Korean historical crime film directed by Wu Jun Xian.