An absorbing all-business first novel about a Houston-based multinational (bearing more than a passing resemblance to COMPAQ and Dell Computer) under siege by a cyberage extortionist whose wry nom de guerre is Hektor. Barry Shepard, the number three man at Simtec (a high-tech enterprise headed by a woman), is mildly disturbed to discover that his company has been delivering wrongly configured PCs to a host of its mail-order customers. When he receives an unsigned letter asking for $1 million to halt the online incursions that are causing the costly problems, Barry immediately informs his superiors. But the mad hacker's timing is impeccable. Less than a year after the installation of marketing whiz Diane Hughes (who barely knows her ASCII from an ellipsis) as CEO, Simtec is still rent by internal strife and unable to mount an effective response to the threat. While the company dithers, Hektor (a.k.a. James Murphy Dupree, a manipulative genius) ups his financial demands to $5 million and intensifies the pressure, misprogramming production-line robots, erasing file servers, destroying backup tapes, and otherwise wreaking in-house havoc. Wall Street and the media catch wind of Simtec's woes, and Barry recruits professional help to join in the increasingly desperate effort to fight and find the blackmailer. The stakes and tension mount as the now mortal enemies stalk one another via the Internet. With a state-of-the-art assist from his independent contractors, Barry eventually succeeds in hunting down Dupree/Hektor and the corporate Judas who gave him an inside track at the embattled company, albeit not before he survives a terrifying crawl through a live-wired cabling duct that has already killed one would-be troubleshooter. An impressively suspenseful, user-friendly debut with appeal both for the barely computer literate and for their nerdy betters. On a scale of one to five, then, four bytes.