This is Hong Kong at the turn of the century. The South China Sea is crawling with smugglers, cut-throats and pirates and none is more successful than the gang led by the notorious pirate Lo. Government forces invariably lose to Lo. Finally the Government looks the other way whenever Lo is around. Young seaman Jackie Chan, so far better known for his bar room fights, resigns from the Marine Force. He plans to stage a personal vendetta against Lo. Jackie gets the help of Samo Hung, little knowing Samo has his own axe to grind. Jackie and Samo suffer an inglorious drubbing in the hands of Lo. Jackie, now completely incensed, decides to don the uniform once again. He finds young commander Yuen Biao sympathetic to his cause but adamant against his antics...