Sci-fi author Bova (Orion and the Conqueror, 1994) branches out with an exciting thriller about entertainment technology in the hands of unstable men. Virtual Reality (VR) scenarios allow people to play baseball with Ty Cobb and Babe Ruth simultaneously, walk on the moon, or sit in the audience to hear Patrick Henry state "Give me liberty or give me death" for an elementary school lesson. Square, reserved Dan Santorini is happy to join his former partner, the brilliant, unconventional, and dangerous Jace Lowery, at ParaReality, Inc., in Florida. The company's president, sexually perverse Kyle Muncrief, plans to use these VR scenarios in an amusement park to rival Disneyland -- if only he can rustle up enough investors. Dan becomes wary when two pilots have strokes in the flight simulator that he and Jace constructed when they worked at an Ohio Air Force base, while his wife, Susan, becomes obsessed with identifying the person(s) invading their 12-year-old daughter Angela's VR lessons at school. Additional danger looms from industrial spies, who have eyed Dan as their next mole, and from Washington insider Quentin Smith, who saves ParaReality financially in exchange for a VR program to control the information flow to the President. The latter elements are not as developed or convincing as the discovery of Angela's victimization or the final shootout, in which the stoic Dan confronts a villain overcome with godlike delusions in a VR scenario to the death. The not-too-surprising moral is that a machine is only as good as its creators, who have human emotions and failings. High-technology in the characters' everyday routines provides a diverting twist to this steadily paced thriller, which should broaden Bova's audience.