After looting the tomb of El Mokanna—the Veiled Prophet—of its precious relics, archaeologist Sir Lionel Barton blows up the tomb. The heretic sect faithful to Mokanna interpret the fireball as their prophet's second coming, and a violent uprising begins.

Dr. Fu Manchu decides to use the uprising and the relics for his own evil ends. Action stretches from Persia to Cairo, then back to London, cultminating in an extraordinary confrontation inside of the Great Pyramid.