In 523 BC the Persian Emperor Cambyses dispatched an army across Egypt's Western Desert to destroy the oracle of Amun at Siwa. Somewhere en route through the burning wastes, the army was overwhelmed by a sandstorm and destroyed. Fifty thousand men were buried beneath the desert sands. Two and a half thousand years later an antiques dealer is murdered in Cairo, a mutilated corpse is found floating in the Nile at Luxor, and a British archaeologist dies in mysterious circumstances at Saqqara. At first the incidents appear unconnected. Egyptian detective Yusuf Khalifa is suspicious, however, and so is Tara Mullray, the archaeologist's daughter. As each seeks to uncover the truth, they find themselves thrown together in a deadly battle for survival, one that forces them to confront not only present day adversaries, but also ghosts from their own past. From a mysterious fragment of ancient text to a lost tomb in the Theban Hills, from the shimmering waters of the Nile to the dusty back streets of Cairo, Khalifa and Mullray are drawn ever deeper into a labyrinth of intrigue, fanaticism, politics and violence, one that eventually leads them into the forbidding wastes of the western desert and the solution to one of the abiding mysteries of the ancient world.