The setting is The Yankee Green - an enormous shopping center/ entertainment mall located in a suburb of Boston. The mall is a self-sufficient, environmentally controlled, electronically secure indoor city; tens of thousands of people pass through its five pavilions every day. The children play in the indoor amusement park; the young professionals work out in the state-of-the-art health club and jog on the atrium's overhead running track; the elderly walk the promenades, sit on benches, chat under the fountains and in the manicured gardens. But the labyrinth of service halls that are weaved into the superstructure lurks a demon: a madman with a grudge, whose plan is to hold five thousand people hostage inside a pavilion he wired to explode.