In the face of government repression and censorship, a number of brave Chinese citizens -- some are activists, others ordinary folks -- are using basic technologies to disseminate the truth about the country's history. Since taking power in 2013, President Xi Jinping outlawed criticism of Mao and rewrote China's modern history to erase the Communist Party's sordid record from the Great Leap Forward to Tiananmen Square and beyond. In this episode, journalist Ian Johnson discusses how the "underground historians" are fighting for China's future by accurately portraying the past.