Martial art film standout Liang Chia-jen brings the same animalistic intensity from his early heroic bloodshed films to his Danger Has Two Faces tough, ex-cop character now relegated to becoming a pet store owner. The stern Police Superintendent Liu played by Chu Chiang sets the stage for his later role in John Woo's The Killer while new comer Fei Hsiang must do Serpico-like things to find out which cop is paid for by the mob.

年捍探周福祥（费翔）的好友金（梁家仁），因误杀余人而引咎辞职，由警察沦为职业杀手。金所执行的多宗凶杀案中，恰巧由周负责这些案中，好友二人一明一暗，在命运安排下，面临生死决。期间周发现一个重大秘密。