One of the best Andy Lau / triads movie. He is magnificent. Louis Koo is also good. Great story and timing. Louis is a top trainee police been chosen to drop out and join HK most powerful triad Hung Hing as undercover. 3 years passed, Louis is doing well in the triad. The triad big boss is Andy Lau, Suki Kwan his wife. Anthony Wong is his right hand man. Patrick Tam is Anthony son just back from England. Louis meet another undercover Eric Wan in the cinema to inform Anthony is going to beat up rival gang selling porno VCD in their turf. Eric ponders if himself is a cop or gangster after so many years. At Andy's mother birthday bash, Frankie Ng bring Lung Fong who later beat up Andy useless god-brother for cheating in a gamble. Andy settle it with money. The undercover try to ask Anthony to back out but fail. The fight escalate and cops arrive. The superior shot Anthony. Lung keep stirring trouble and Andy kick him down the escalator. Louis and him go hospital to visit Anthony. Andy has quit as triad for 5 years and do legit business but still gangsters find troubles with him. The superior refuse to let anyone see Anthony who is hurt in the spine. Andy ask for favour to let Patrick in and is rejected. His face changed immediately and the superior relented. Joey Meng is Louis girlfriend. Eric feel so bad when Anthony is shot. Louis handler has change to another bad attitude superior. He want Louis to nail Andy with the crimes. All the seniors want Andy to return as the boss but he decline. Patrick daringly stand up and say there's more than one undercover amongst them and whoever can find them out is worthy to be the boss. Andy task Louis to check on Eric who went missing since the incident. He decided to quit police and escape with his son out of HK but gangsters attack his home. Frankie throw the boy to a car windscreen and Patrick kill Eric. Louis is too late to warn him. Patrick visit Anthony and says he will snatch back Andy wealth, power and wife and blame him for been useless. Andy also came and Patrick quickly admit to killing Eric and lied that it is Anthony that says he is undercover. Patrick ask Louis to help him since he and Eric were close. He want Louis to kill the cop that shot Anthony. Andy now only trust Louis. At a home dinner, the godbrother plead with Andy mum to lend him $500k or be kill by rival loanshark. Andy beat him up and shows his authority when even Suki and his mum cannot interfere. He only give Louis face when he ask him to stop. The godbrother put up at Louis home. He try to peek at Joey in the shower but she anticipated it and whack him with a cane. Patrick call Louis to meet and discuss with the rival gang and bring the godbrother. Patrick blame the rival gang boss he call the cops to catch Anthony and ask him to get out of their turf. He also send people to kill his family and says everything is Andy instruction. The fight escalate and the boss caught the godbrother. Louis is caught by the cops in ambush. The superior doesn't believe that everything is done by Patrick. Joey pretend to be drunk and enter the room book by Frankie and Lung. She hear them discussing about an attack on Andy and Suki, who is playing mahjong with 3 planted friends. Joey pretend to vomit and left to warn Suki. She and Joey arm themselves with knives and manage to escape in a coming car. The godbrother visit Andy home but is an ambush by the rival gangster. Andy let them catch him and want his family release. Patrick appears and says everything is his doing. Lung kill the boss on the spot. Patrick want Andy to sign legal document to pass all his assets to him. The superior release Louis because he have arrest warrant for Andy. The rival gang boss dead family are pin under his doing. Suki and Louis decide to act on their own now. She find Patrick in the office. Louis attack the henchmen and overtake the situation. Andy warn Lung if he torture his mum and son he will pay. Louis point a gun at Patrick and tell the rest that he is gonna escape with all the money. In a split moment, Lung shot Louis who shot him back. The godbrother let the mother and son escape. Frankie shot him at the back, he lunge towards him and push him to a piercing pole and both died. Suki drive a car and save Andy and Louis. Suki is shot dead by Patrick. Andy return to power and Louis ask him to call police and says he is a cop. Andy says he knew his identity long ago. The doctor knock him unconscious and Andy plan for revenge. He find Anthony and the latter also agree to kill Patrick. He is going to take the cash out when the cops came to arrest him. Louis identify himself as cop and Patrick is surprise. He hold the superior hostage and shot him. He shot Louis and escape to the roof. Andy awaits him at the roof and gonna throw him down. Louis tell him to stop as he came so far to stay clean. Andy turn and walk away. Patrick take the gun and want to shoot and Louis shot him dead. The gun is empty and Andy plan all this in advance. He got his revenge and stays crime free.