The first published novel in this bestselling series asks the question: "What if the basic human nature suddenly changed?" Hugh Valleroy of the Gen Police undertakes a covert mission into Sime Territory to rescue the woman he loves from the Sime kidnappers who would use her to destroy his government. His protector and guide?—a Sime who carefully and deliberately plans to kill him!

The New York Times Book Review says of the Sime~Gen Series that "It calls to mind the Frank Herbert of Dune and the Walter M. Miller, Jr. of A Canticle for Leibowitz."