Customs Frontline

The plot centers around Zhou Zhengli (played by Nicholas Tse), an assistant director of the Hong Kong customs department, who shares a deep, mentor-like relationship with his superior, Zhang Yunnan (played by Jacky Cheung). As they investigate a case of arms smuggling, they find themselves under violent attack from foreign forces. In response, Zhou Zhengli gets assigned to carry out a joint operation with Interpol, infiltrating active arms-trafficking hotspots overseas. During the investigation, Zhou Zhengli discovers potential traitors within his own department. He alerts his superior in Hong Kong, Zhang Yunnan, and together they confront the internal betrayers. However, the truth turns out to be even more shocking than they could have imagined.