"Sphinx," a wordy thriller about black-market intrigue in Egypt, is as inert as its many mummies. For a few chapters, the reader wonders whether they are inert at all. The references to the "Curse of the Pharaohs," the ominous flashbacks to ancient Egypt, and the mysterious deaths of tomb-violators all suggest that an avenging mummy will soon emerge. Mr. Cook, however, exploits the mummy-tale formula for other purposes. Coinciding neatly with the King Tut craze, his interest is in the material glitter of Egyptian artifacts. These he describes in intricate detail, as if to deflect attention from the tedious plot….

Even Mr. Cook's sense of place and history, the novel's one strength, is compromised by triteness: "It must have been a fascinating era, full of turmoil, upheaval, and emotion." Making adventure-story clichés work requires at least a modicum of self-awareness and humor…. But when Mr. Cook writes...