Arriving in Cairo for another thrilling excavation season, Amelia Peabody is relaxing in a well-earned bubble bath in her elegant hotel suite in Cairo, when a man with a knife protruding from his back staggers into the bath chamber and utters a single word --- "Murder" --- before collapsing on the floor. Among the few possessions he carried was a sheet of paper with Amelia’s name and room number, and a curious piece of pasteboard the size of a calling card bearing one word: "Judas." Most peculiarly, the stranger was wearing a gold-rimmed monocle in his left eye. It quickly becomes apparent that someone saved Amelia from a would-be assassin --- someone who is keeping a careful eye on the intrepid Englishwoman.

It's true: the last camel is gone, leaving Amelia, Emerson and Ramses to bake under the desert sun in the winter of 1897. Armed with a mysterious note and map, they have been commissioned to locate a lost English aristocrat and his wife, who disappeared over a decade ago.