In a cinema at 20th Century Fox Studios in Los Angeles, a woman stands on stage and introduces clips from the new Ridley Scott movie. Exodus: Gods And Kings tells the story of the flight of the Hebrews from Egypt as led by Moses. Its famous director certainly hasn’t welched on duties in the biblical epic department: against some competition, it’s his most expensive film. Spectacular cities have been constructed, battle scenes with thousands of extras have been mapped out (thousands more were added by computer), the Red Sea has been parted. It stars Ben Kingsley, Sigourney Weaver and the Australian actor Joel Edgerton as no-good Egyptian Pharaoh Ramesses II.