The president loses control of fifty nukes for nearly an hour. Russian nuclear bombers almost bump wingtips with American fighter jets over the Pacific coast. North Korea's madmen detonate nuclear weapons underground. Iran's nuclear shroud is penetrated by a computer worm. Al Qaeda goes on the hunt for Pakistan's bomb, and Israelis debate the merits of a preemptive nuclear strike. Treaties are signed, but thousands of nuclear weapons are still on hair-trigger alert. This is how the end begins.