When a container ship mysteriously turns up in Hong Kong waters, local Customs officers sail into dangerous international drama. After boarding the vessel, a team led by Cheung Wan-nam (Jacky Cheung) and including young hotshot Chow Ching-lai (Nicholas Tse) discover dead bodies of crew members and a huge cache of arms, including a valuable compass suited for use in a submarine. The customs officers don't know it yet, but an international incident is about to blow up...