A police officer receives a worn-out and traumatised woman who begs him to take actions against a ruthless man that ruined her life, and only gives his moniker, Tín Mã Nàm, meaning “crazy horse” in Cantonese. As the officer sets out to search for Tín Mã Nàm, a network of intricate crimes, espionage and bloody murders beyond his imagination begins to unfold.

Hai duong trang was produced in 1994 as a dramatic crime romance film. The film comes from a real character - the infamous robber general Bach Hai Duong.