In the last seven years of Mao Zedong's life, he twice made important decisions in the south, twice changing China's destiny and historical direction. This book uses a large number of historical witnesses' memories and original materials such as the trial records of the Lin Biao Group of the Special Court of the Supreme People's Court of the People's Republic of China. It uses conclusive evidence to answer various "legends" about the "September 13" incident at home and abroad and restore the true nature of history. The author of this book has followed Mao Zedong's actions during his southern tour for dozens of times and conducted on-the-spot research, exclusively revealing the ins and outs of Mao Zedong's actions and thoughts and all major decisions during the last 270 days he left Beijing in his life.