The Emperor (Ge You) usurped the throne by murdering the previous Emperor. He marries the Empress (Zhang Ziyi), wife of the previous Emperor and stepmother to the Crown Prince (Daniel Wu). At first the Empress seeks only to protect herself, but as the new Emperor grows suspicious of all those around him, she realizes that only by helping the Crown Prince kill the new Emperor can she hope to survive. Together with the Chief Minister (Ma Jingwu) she tris to carry out this plot. But when the Prince is wraked by indecision, she devises a new plan and seeks the throne for herself.
The Crown Prince was never interested in court politics and did not look forward to becoming emperor. He instead pursued a life of art. When he faces the need to kill the man who murdered his father and usurped the throne, he is torn between his desire for revenge and his instinct for peace. The Princess (Zhou Xun) he is engaged to loves him unreservedly, but as she watches him drift away into melancholy and confusion, she falls into unreasoning passion.
The Empress was originally to be the Prince's mother, rather than stepmother, but when Ziyi choose to take the role, they made the switch since she is too young to play a woman old enough to be Daniel Wu's mother.