1942. Rommel a pris Tobrouk et l’Egypte est sur le point de tomber aux mains des nazis. Dans le grouillement du Caire où le destin vacille encore, une lutte à mort s’engage entre un espion allemand qui, à l’abri chez sa maîtresse, une voluptueuse danseuse égyptienne, transmet chaque jour des renseignements à Rommel en utilisant un émetteur radio et un exemplaire de Rebecca de Daphné Du Maurier contenant la clef du code, et un major des services secrets britanniques. Lui a pour aide Elen, une jeune juive égyptienne prête à utiliser sa beauté pour combattre les nazis.

He is known to the Germans as 'Sphinx', to others as Alex Wolff, a European businessman. He arrives suddenly in Cairo from out of the desert, armed with a radio set, a lethal blade and a copy of Daphne du Maurier's Rebecca – a ruthless man with a burning, relentless conviction that he will win at all costs. The stakes are high, for the survival of the British campaign in North Africa is in the balance. Only Major William Vandam, an intelligence officer, and the beautiful courtesan Elene can put an end to Wolff's brilliant clandestine reports of British troop movements and strategic plans. As Rommel's troops come closer to victory, Vandam edges nearer to Wolff and the crucial key. Follett builds tension and suspense to a nerve-tearing pitch as he follows the adversaries across the infernal desert to a confrontation which will determine who wins – and loses – in this deathly struggle.