When the son of a gang leader manages to insult the son of a rival gang leader, total war erupts between the rival gangs, and the young hero is forced to do terrible things in order to maintain order and honor.

An assassin known as Wind Yip (Sharla Cheung) is thought to be a robot after she is seen ripping the guts out of the president of a large corporation and dodging a hail of bullets from police. Later, she shows up at the corporation to steal the Diamond of Emperor Chen which is the key to a vast treasure. But another group of thieves, led by Ko Kit (Anita Yuen), are also trying to steal the diamond for their boss who has labeled the operation the Crystal Fortune Run. After guards are alerted, Ko takes the jewel and leaves Wind to fend off the guards.

Five cops work and get on each other's nerves during a hot summer. Tak is a gambler, too much so for his girlfriend to risk marriage. Daddy, a single father, is harsh with his son who reminds him of the woman who abandoned them. Monk is mercurial, talkative, a show-off. Kong, a steady family man, keeps the peace. Sam is new, hoping to fit in and make it as a cop. Three brutal and murderous robbers are on the loose, and so is a former soldier, embittered over the loss of his pension, using very real bombs to extort what's due him. It's a dangerous job, and the cops must watch each other's back, regardless of their personal problems.