LI Xiangchuan is an expert in the city museum,living a causual and rich life in an old villa in the downtown area. His girlfriend CHENG Meimei is a lawyer, who cannot tolerate his sluggishness, much too content dispositon and no-marriage attitude, plans to go to the south America to earn her life. Before leaving, she asks her intimate XU Zhujun, an associate professor on sex, to come over to take care of LI Xiangchuan, which is actually 'watch over'. But on returning from abroad, CHENG Meimei finds her boyfriend and her intimate should have had developed in their romantic feeling toward each other. Even though the three maintain their previous relationship superfacially, CHENG grows more and more impatient and demand Li Xiangchuan to wed her. With Li in a dilemma and XU's not quitting, the three reach a deadlock, by which time Li gets involved accidentally in a sinister project smuggling cultural relics and his life is in danger.
