John (played by 任达华) escapes from Vietnam and helps out on his brother's cargo ship in the Philippines, only to find out that his brother is involved in murder and trafficking, making a fortune but accumulating blood debts. One day, while the cargo ship is en route to Hong Kong, they encounter a group of trapped Vietnamese refugees at sea. The crew pretends to rescue them, but reveals their true intentions with knives once the refugees are on board. John recognizes his old friend Garry (played by 周景扬) and fights desperately to save him, but Garry loses his memory in the process of the struggle. The cargo ship is inspected at the Hong Kong dock, and the unidentified Garry injures a police officer and jumps ship to escape, leading to the ship being detained by authorities. Fearing that Garry will expose their murderous trafficking activities, the captain orders crew members to hunt him down. In the following days, multiple murders occur at the dock. A female inspector from the Hong Kong police (played by 杨丽菁) investigates and learns that the cases are related to the fleeing Garry, prompting her to initiate a manhunt, but during the process, she discovers deeper secrets...