This text contains the introduction, commentary and script for the film "Viva Zapata!". It tells the story of the part played by Emiliano Zapata in the Mexican Revolution, championing the cause of the peasants between 1909 and 1919. The author describes the history, customs and character of the abused and rebellious peasantry and their natural leader, Zapata. The book combines two of Steinbeck's lifelong interests, his concern for the underdog and for the artistic potential of the cinema.