Mr. Zhao, Lu Yue's intimate study of marital infidelity, is a rare Chinese import: It's neither the sort of opulent period piece associated with other Fifth Generation filmmakers nor a flashy, hyper-kinetic Hong Kong art picture. Lu, the ace cinematographer behind Xhang Yimou's Shanghai Triad and Joan Chen's recent Xiu Xiu: The Sent Down Girl, eschews his usual bright color schemes for pared-down, documentary-style realism. Incisive and emotionally raw, the film illuminates a private side of contemporary Chinese society that Westerners rarely get to observe. Set mostly in cramped, suffocating Shanghai apartments, Mr. Zhao stars Shi Jingming as a sullen middle-aged teacher conducting an adulterous affair with former student Chen Yinan. When faithful wife Zhang Zhihua catches them together, she's devastated but unwilling to pursue a divorce for the sake of their young son. Unrepentant, Shi continues his infidelity until Chen reveals she's pregnant and demands his commitment. In long, beautifully improvised takes—the first 40 minutes cover only about three scenes—Lu sketches these troubled relationships with piercing clarity and emotional truth. Though mild-mannered and charming, Shi's character is slowly revealed to be something of a monster, incapable of feeling any responsibility outside himself and his own gratification. Mr. Zhao is a passionate and deeply ironic social critique that finds traditional marital bonds gradually fraying at the seams.