Tang Wei, making her film debut, plays Wang Jiazhi, an idealistic young woman who is first introduced as an upper-class socialite making a house call on Mrs. Yee (Joan Chen). Mrs. Yee is married to Yee (Tony Leung), a high-ranking Chinese collaborator in a Japanese-occupied Shanghai of 1942.

It turns out that Wang is part of a group of former university students, led by Kuang (Wang Leehom), who plan to assassinate Yee. Wang has gone deep undercover, with the intention of seducing the head of the Yee household.

The ultimate aim is to get the guarded Yee out into the open, where he can be shot, but Wang finds that she loses her own identity in the process. Meanwhile, the dynamics between the anti-Japanese freedom fighters become more complicated when Wang's feelings for Kuang, the leader of the pack, don't appear to be reciprocated.

Tang does an excellent job of conveying Wang's emotional turmoil. She holds the picture together with a controlled performance that lets loose at the right moments. Even though he gets top billing, Leung is really a supporting player. He wisely lets Tang become the focus of their scenes.