In 1995, a large-scale armed robbery occurred in Guangdong. A bank cash transport vehicle was robbed by five armed robbers, with a loss of up to 15 million yuan. Three cash escorts were killed in the incident. The incident shocked the whole country. The Public Security Bureau immediately set up a special case team. The criminal police led by Wang Shouyue (played by Lam Ka-tung) and He Lan (played by Zhang Songwen) quickly searched for evidence, successfully grasped the whereabouts of the five robbers and arrested them one by one. Surprisingly, the robbers confessed that the real planner behind the case was Chen Xinwen (played by Dapeng), the boss of a construction company, and his cousin Chen Xinnian (played by Sun Yang). Chen Xinwen and Chen Xinnian failed and embarked on the road of escape, and disappeared from the world. Twenty-one years have passed, and the case of that year has long faded from the public's view, and Wang Shouyue has also retired from the Public Security Bureau. However, a blurry figure appeared in an ordinary video, which rekindled his hope of solving the case. Wang Shouyue went to the border city alone to find the "stranger" in the video. The final showdown between good and evil officially began twenty-one years later.