Atbara, Sudan, 1913. A dead man is fished out of the River Nile. An accident – or something more sinister? A visiting Pasha from the Royal Household believes it was murder – and that he himself was the intended target. He insists that the Mamur Zapt, Head of the Khedive’s Secret Police, escorts him on his return train journey to Cairo, for protection.

It’s to be an eventful voyage. Matters take an unexpected turn when the train is stranded in the desert following a sandstorm. With the help of English schoolboy Jamie Nicholson, the Mamur Zapt pursues his investigations, convinced that at least one of his fellow passengers has a secret to hide. And what was the Pasha really doing in that remote corner of the Sudan? Could the Mamur Zapt’s deepest fears be true? Could he really be about to uncover a conspiracy against the British?