Rising out of the stony canyons of Nevada, Utopia is a theme park attracting 65,000 visitors each day, with its dazzling array of robots and futuristic holograms. But ominous mishaps are beginning to disrupt the once flawless technology. A friendly robot goes haywire, causing panic, and a popular roller coaster malfunctions, nearly killing a teenaged rider. Dr. Andrew Warne, the brilliant computer engineer who designed much of the park's robotics, is summoned from the East Coast to get things back on track. On the day Warne arrives, however, Utopia is infiltrated by a group of ruthless criminals who now have access to the park's computerized infrastructure. Their communication begins with a simple and dire warning: If their demands are met, none of the 65,000 people in the park that day will ever know they were there; if not, chaos will descend, and every man, woman, and child will become a target. As one of the brains behind Utopia, Warne finds himself thrust into a role he never imagined--trying to save the lives of thousands of innocent people. As the minutes tick away, Warne's struggle to outsmart his opponents grows ever more urgent, for his only daughter is among the unsuspecting crowds in the park.