"The Elephant Mask" is the fourth "Humboldt Prior Mystery." Now an aging executive of a troubled computer company, Prior is given responsibility for a promising new project that applies computer science to Latin American archeology. From the ruins of the ancient Moche people, the project surfaces the strange problem of the Elephant Mask and then nearly dissolves in a mysterious triple assassination. Prior travels to Lima, Peru to try to salvage the project. There, he is entangled by unscrupulous enemies, unpredictable old friends, and the assets and liabilities of his distant past. In Peru, New York, and San Francisco, Prior must weave his way through a maze of attempted seduction, trickery and betrayal, further killings, and cutting edge software technology. To survive, he must solve the triple problem of the murders, the underlying crime, and the age-old mystery of the Elephant Mask. Beneath an enormous relic of military technology, the story ends in an unexpected, ghastly execution, and more of Prior's past reaches out to him.