could see, underwater and close-up, the menacing shadowy figure of a submarine gliding through the crystal blue sea.

He saw, too, a patrol plane as it spotted the submarine and sent an urgent radio warning.

The underwater picture dissolved in a bewildering burst of bubbles. A missile had been launched. Within seconds, another burst—this time a nuclear depth charge—utterly destroyed the submarine.

It was confusing. He was everyplace at once. The details were overpowering, but the total picture was agonizingly clear.

Six submarines fired missiles from the Gulf of Mexico. Four were immediately sunk, but too late. New Orleans, St. Louis and three Air Force bases were obliterated by hydrogen-fusion warheads.

The CIA man was familiar with the opening stages of the war. The first missile fired at the United States was the signal for whole fleets of missiles and bombers to launch themselves at the Enemy. It was confusing to see the world at once; at times he could not tell if the fireball and mushroom cloud was over Chicago or Shanghai, New York or Novosibirsk, Baltimore or Budapest.

It did not make much difference, really. They all got it in the first few hours of the war; as did London and Moscow, Washington and Peking, Detroit and Delhi, and many, many more.

The defensive systems on all sides seemed to operate well, except that there were never enough anti-missiles. Defensive systems were expensive compared to attack rockets. It was cheaper to build a deterrent than to defend against it.

The missiles flashed up from submarines and railway cars, from underground silos and stratospheric jets; secret ones fired off automatically when a certain airbase command post ceased beaming out a restraining radio signal. The defensive systems were simply overloaded. And when the bombs ran out, the missiles carried dust and germs and gas. On and on. For six days and six firelit nights. Launch, boost, coast, re-enter, death.

And now it was over, the CIA man thought. The missiles were all gone. The airplanes were exhausted. The nations that had built the weapons no longer existed. By all the rules he knew of, the war should have been ended.

Yet the fighting did not end. The machine knew better. There were still many ways to kill an enemy. Time-tested ways. There were armies fighting in four continents, armies that had marched overland, or splashed ashore from the sea, or dropped out of the skies.

Incredibly, the war went on. When the tanks ran out of gas, and the flame throwers became useless, and even the prosaic artillery pieces had no more rounds to fire, there were still simple guns and even simpler bayonets and swords.

The proud armies, the descendents of the Alexanders and Caesars and Temujins and Wellingtons and Grants and Rommels, relived their evolution in reverse.

The war went on. Slowly, inevitably, the armies split apart into smaller and smaller units, until the tortured countryside that so recently had felt the impact of nuclear war once again knew the tread of bands of armed marauders. The tiny savage groups, stranded in alien lands, far from the homes and families that they knew to be destroyed, carried on a mockery of war, lived off the land, fought their own countrymen if the occasion suited, and revived the ancient terror of hand-wielded, personal, one-head-at-a-time killing.

The CIA man watched the world disintegrate. Death was an individual business now, and none the better for no longer being mass-produced. In agonized fascination he saw the myriad ways in which a man might die. Murder was only one of them. Radiation, disease, toxic gases that lingered and drifted on the once-innocent winds, and—finally—the most efficient destroyer of them all: starvation.

Three billion people (give or take a meaningless hundred million) lived on the planet Earth when the war began. Now, with the tenuous thread of civilization burned away, most of those who were not killed by the fighting itself succumbed