Following the ransom of Rima Barton Fu Manchu and the escape of Fu Manchu from the closley guarded pyramid of Giza Nyland Smith tries again to bridge the blank period in Sean Greville's memory but he recalls only the phrase, he'll be crowned in Damascus spoken to him by a beggar.

On a hunch Smith flies to Damascus where he learns from Glendenning, a British secret service agent, of a mass gathering of natives to be held in the great mosque of Damascus. At this meeting the reborn prophet is to be crowned. Disguised as natives, Smith and Glendenning go to the meeting where Smith denounces the new Mocana as an imposter...