A knife can be used to kill a person, yet it can be used to save a person.

Li Fei is mad on knives.  He has kept various types of knives at home.  He especially likes to let

fly knives for fun and very seldom misses his targets.

Chan Kin Ming, a Hong Kong merchant, is willing to pay a hundred thousand dollars to Fei to kill

a man, but Fei refuses.  Later on, Fei is unemployed.  Ming persuades Fei to kill a man called Chan

Chun Choi by telling him Choi is a man deserving death and promises to give Fei a greater reward. 

Fei begins to change his mind.

Fei finds Choi in a bar and learns that he has deserted his wife and his seven-year-old son. 

So, Fei decides to kill him.

However, seeing his ex-wife living in poverty, Choi wants to turn over a new leaf and

make up for his wrong-doing.

Fei feels upset about it.  He doesn’t know what to do.

One day, Fei has discovered that Ming and Choi are brothers born of different female parent.

Ming wants to kill Choi for legacy.