It is a loose adaptation of the 1980 television series The Bund in many respects, even though it was done by narrating the action in three segments, each featuring the main characters of the film.

The story was set in Shanghai during the Republican era, when the city was dominated by triads shortly before it was occupied by the Japanese in the Second Sino-Japanese War.

Hui Man-keung (Leslie Cheung), an agent the Taiwan People's League participates in fighting against Japanese invaders with his fellow comrades.

Hui becomes seriously injured in a gunfight with the Japanese and falls in the water, and ends up in Shanghai and is found by Ting Lik (Andy Lau), a young, low-class labourer but dreams being a powerful triad leader.

Ting becomes more and more ambitious and kills another triad leader and the police chief while also expresses his love for Ching-ching and wins Fung's approval.

It turns out Hui and Ching-ching met during the summer last year in Northeast China while the former was being chased by the Japanese and had a brief romance but he did not know her name and was shocked she was the woman who Ting was in love with.

Uncle Lau pleads Ting to care for Ching-ching as well as avenging Fung as everyone in Shanghai is fighting to kill Hui.