On the night of September 12-13, 1971, Lin Biao, Mao Zedong's officially recognized closest comrade-in-arms and chosen successor, was killed in a mysterious plane crash in Mongolia. The Chinese government did not issue an announcement of Lin's death, and it became generally known only in the summer of 1972, when the official explanation stated that Lin had masterminded plans for a coup d'etat and the assassination of Mao, and died fleeing to the Soviet Union after both plans had failed. But no convincing proof was offered to substantiate these claims, and the Lin Biao incident has remained an...