Detective Chan Kwok-chung is nearing retirement but remains determined to put an end to the reign of crime lord Wong Po. Despite Chan's valiant efforts, Wong Po evades legal justice due to lack of evidence, largely thanks to his loyal and ruthless henchmen. When Chan's terminal cancer diagnosis creates additional urgency, he becomes more desperate and willing to bend the rules to ensure Wong Po's capture. As Chan's health declines, he forges an uneasy alliance with his successor, Inspector Ma Kwun—an incorruptible and skilled martial artist with a strong sense of justice.

Unbeknownst to Ma, Chan and his team resort to morally questionable tactics to finally catch Wong Po, planting evidence and crossing ethical lines. When Ma discovers the true extent of this conspiracy, he is torn between his duty to uphold the law and the necessity of stopping the ruthless Wong Po. The tension between the two approaches escalates, culminating in a series of brutal confrontations. As the detectives close in on Wong Po, they must navigate the fine line between justice and vengeance, leading to an explosive and heartrending showdown.