The year is 1971 and former champ Muhammad Ali--stripped of his title for refusing to fight in the Vietnam War--has come to New York to face unbeaten Joe Frazier for the undisputed heavyweight championship of the world. Award winning filmmaker William Greaves goes behind the scenes at what is still called "The Fight of the Century", including the training, the press conferences, the negotiations, the celebrities and the controversial 15 round battle itself. This is Ali at his funniest, prettiest, fiercest and fastest, in a still spinning look at the fighter known simply as The Greatest.