A top nuclear scientist goes mad and takes an innocent family hostage at gunpoint, killing one and causing a massive standoff. A plume of radiation above New York City leads to a warehouse where, it seems, a powerful nuclear bomb was assembled just hours before. Sifting through the evidence, authorities determine that the unthinkable is about to happen: in ten days, a major American city will be vaporized by a terrorist attack. Ten days. And Gideon...