SIN agrees to co-operate with the police after listening to the advice from Police Officer, LEUNG. But, HERO and GI think that SIN is scared to have troubles and dare to report the indecent behaviour of SANG to the police. Meanwhile, owing to the inexperience of GI, she forgets to record the speed of YEUNG during the chase last time. Her mistake lead to the withdrawal of charge against YEUNG eventually. HERO demonstrates the fastest speed of changing tyre, whilst his best old friend, TANG KIM HO encourages HERO to be an engineer again and help MARK in the car racing at Macau. Coincidentally, YEUNG also tends to invite HERO as engineer in the same car racing. With rages from rejection, YEUNG provokes HERO in the street. But due to the commitment to her daughter, HERO purposely crashes his car and hurts himself in order to get rid of the disturbance of YEUNG. With the help of SIN, SANG finally arrests all criminals of the car robbery.… ...