The Incursion

Author of The New Alchemists, a nonfiction account of Silicon Valley, Hanson has turned his considerable expertise to fiction, and the result is an excellent thriller. When the nation's most important, and presumably most secure, computer systemcode named SEEKis compromised, the world's financial and health-care systems are jeopardized, along with the launching codes for America's ""Peacemaker'' missiles. Implicated in the unauthorized entry into the system's upper levels is Peter Cassidy, a young physicist who has turned in his chips for a fishing rod until the DID Corporation, which operates SEEK, brings him in. To clear himself, Cassidy must find the true culprit, who has threatened a second, more damaging incursion into the system. Hanson keeps his high-tech thriller alive with taut action and strong characters, including a couple of odd-ball computer geniuses, one of whom is financing a giant rock concert that plays into the book's exciting finale. While some of the threads don't pull together as neatly or tightly as they might, this is still an exciting and suspenseful narrative. (April 28)