Lung was an informer of Police in the triad society. But his identity was exposed and lost all memory after hurt .All of money that given by the Police was lost. The Police suspicious Lung had hidden the money. So he was wanted by the triad society and Police.

Sing was a little thief, he knew Lung and made friend together .He knew everything about Lung then, and he wanted to help Lung to recover his memory aimed to take back the money.

Fong was a manger in a big firm .He had stolen a large amount of money of his firm and was discovered by his colleague later .So he wanted to kill Wu but failed. Fong also wanted the money of Lung ,as a result ,he wanted to kill Lung also .Wu was saved by Lung and Sing. The Boss of Fong knew everything were exposed and ordered Koo to kill Lung, Sing and Wu. But Wu won’t do that because of their friendship…