With a camera and one simple question, the Chinese filmmaker Liu Wei heads for the University of Beijing and Tiananmen Square. "Do you know what day it is today?" he asks passers-by, mainly students and young people. "June 4th, 2005," most people answer correctly, but many of them already guess where the conversation is leading. This is the 16th anniversary of the student uprising at Tiananmen Square, which was bloodily quashed by the government.