Nuclear war, deterred for decades by the threat of mutual annihilation, has begun. Al-Qaeda, unconcerned with the consequences of its actions, has detonated a bomb in Washington D.C., destroying the nation's capital. As President McCormick and his advisers face the tough decision of whether to follow through with their threat to retaliate against the perpetrators, a new challenge arises-one as potentially deadly as nuclear war. Once again, the president turns to his old friend, Dr. Amos Blund, for help-but will it be too late? Can Amos help the president avoid global thermonuclear war and the horrors it will unleash? Struggling to control infighting in the Preserve, Amos faces a daunting task. Helping the president face global challenges, as he must, while also reeling from the staggering, nearly incomprehensible discovery of a gate-to somewhere or to somewhen-Amos must decide where his priorities lie, especially when worlds collide.