Tantalus: Behind the Mask follows the tumultuous creation of one of the most ambitious feats in the modern theatre -- the 12-hour recreation of the Epic Cycle, the sprawling Greek creation story which spawned all of Greek mythology. The production became a struggle between writer John Barton and director Sir Peter Hall, who had been fast friends since founding the Royal Shakespeare Company in 1961, but left the battlefields of Tantalus bitter enemies.