Ah Sing want to be a cop since small, but lack of good eyesight, he only can do as transportation proctor.  One day, a robbery occur while he is on study, he furiously assists for the police to chase the thief and come across with his old friend Johnny, He envy Johnny been a cop, but unexpectedly, Johnny has misappropriated the ill-gotten money when he pursue the thief and plans to go away. Not so far, Johnny really disappears, Sing felt strange and takes the responsibilities to looks after Johnny’s girlfriend Linda. In another hand, he cooperate with gangster to seek Johnny, as their money was stolen, they threat Sing for forcing Johnny to be shown up. Sing pretends as a cop to investigate the case with his self learning technical. Unexpectedly, he found the truth why Johnny took away all the money.  Finally Johnny appears…