Only six major railroad bridges cross the Mississippi River between St. Louis and New Orleans. When one of them collapses, Assistant Director Hush Hanson of the FBI is asked to organize a federal task force to investigate. Evidence points to a bomb, but there are no clues to suggest who planted it.
One night after a second bridge accident, an Air Force C-130 crash-lands on a secret military installation in Alabama, and its deadly cargo has to be transferred to a military train. Within days, this train must cross the Mississippi River before its cargo becomes dangerously unstable...but then another bridge goes down in the night.
As the Bureau and the task force scramble to find the perpetrators, internal FBI politics begin to coil around Hanson and his task force deputy, the alluring senior special agent Carolyn Lang. In the midst of a national transportation crisis, Hanson finds himself fighting on two fronts he knows about and one he doesn't.