The rocket had started slowly as these great towering constructions do. The first blasts barely served to push it away from its launching guides. It seemed to tremble in every plate as if precariously perched upon the short, furious blast of yellow. Then the fiery tail lengthened as the tall, thin metal body rose slowly, lifted like a thin white pencil on the roaring cataract of burning gases.

Now it was its own length from the ground, now pushing up faster, giving in split seconds the curious impression that it might topple over at any instant. But the steady rise gained in speed, the rocket pushed away from its burning tail ever faster, the fire turned from yellow to blue, and within a few more blinks of the eye it was hurtling into the sky, vanishing into a dot, and then was beyond sight.

To Robin it seemed again as if a giant hand were pressing down. He felt it spreading over his body, felt himself being pushed relentlessly by superior weight against the matting of the compartment floor. His head was thrust down as if by a giant forefinger of this invisible monster leaning over him. Now it seemed as if the giant, in maniacal malice, was leaning his weight on his hand, pressing on Robin, trying to shove him through the floor if possible.

He gasped for breath, could barely catch it against the growing pressure on his chest. His eyes sank into their sockets and he tried to close them but found the effort too much.

All about him there was a roaring sound, a humming and thrumming, and now began a thin, piercing whistling, which was the air outside rushing past. The whistle rapidly increased to an ear-splitting shriek, then vanished, leaving eddies of unheard auditory vibrations. Robin tried to close his mouth, which had been forced open by the prying finger of pressure. He felt as if in another moment he must cave in, be squashed flat. His brain reeled dizzily, then suddenly a merciful blackness fell over him and he knew no more.

At that very moment, though he could no longer sense it, there was a click, audible through the length of the vibrating column of metal, and the first section snapped off. Its great fuel tanks, so full of volatile gases an instant before, had emptied themselves in a fury of chemical combustion. The automatic releases had loosened the whole bottom half, the main fuel section, thrust it into space to fall and shatter upon the desert miles below. At that same split second, another series of relays touched off the second firing section.

The new firing tubes blasted into action. Of a design different from those that preceded it, of a design new to the world of man, the experimental jet burst forth. For an instant it seemed as if the pressure had vanished in the rocket, for a split second the rocket stopped accelerating as it waited for the new impact. Then like a blast of lightning newly released from a storm, a shot of energy flashed through the racing metal body. The giant hand came down on everything within it with a firmness and power not sensed before.

There was a blast now emerging from the tail of the flying rocket something like that of an atomic bomb, but not quite. It was not an explosion, but an atomic reaction. It was a rocket flare of an intensity and heat beyond all the potential of mere chemical reactions. It was atomic fire, chained and harnessed to the tail of a rocket.

The thin white pencil, reduced in length, raced on into the dark stratospheric sky.