Number one was a Chinaman - the greatest criminal of all time; Number two was a multi-millionaire; Number three was a beautiful French woman; and Number four was "the destroyer," the ruthless murderer, with a genius for disguise, whose business it was to remove those who interfered with his masters' plans. These four, working together, aimed at establishing a world dominion, and against them were ranged Hercule Poirot, the little Belgian detective with the egg-shaped head and "little grey cells," and his friend Hastings.