Gaddon tensed in the darkness, gripping the safety straps he had attached to himself. Beside him he felt the cat let out a frightened mewing sound as the roar of the exploding rocket power grew. He felt the furry body rubbing against his side, seeking sanctuary against this dread sound. And then the rocket trembled with sudden movement. It was slow at first, but then it grew faster, and Gaddon felt a faint intensity of fear in his temples at the shuddering power of that movement. And then he felt the blood draining from his head, making him faint with dizziness as the rocket accelerated suddenly into a terrible burst of speed. He could feel it moving swiftly through the atmosphere now, feel the tortured rush of air that whipped against the sides of the projectile in a moaning dirge that mingled with the roar of the exploding rocket fuel. And as the seconds passed, he became accustomed somewhat to the increasing velocity of the projectile, and the dizziness passed from his head. Then he became aware of the trembling body of the cat beside him and a soft laughter rose in his throat. But it died stillborn as the roar of the rockets grew to a thundering hiss now in his ears. And he felt the cool sweetness of the automatically released oxygen fill the chamber about him and he drank it into his lungs hungrily. With each second now, he knew the projectile was racing higher into the rarefied atmosphere, heading steadily out to where the air of earth would be almost non-existent. And a grim smile crossed his face in the darkness, for he knew that shortly the rocket would enter the outermost layers and the cosmic rays would play with all their energies upon the projectile. And he tensed suddenly. There was a glow that sprang into being in the chamber about him. It was dim at first. But it grew steadily in intensity around him, revealing the interior of the chamber in its weird light. An exultation swept through him then. He knew they had entered the field of the cosmic rays, and that the manifestation of light he saw was a result of those forces of nature. Beside him the cat mewed plaintively in fear and huddled closer against Gaddon's body. His eyes watched the tiny creature for a moment and then swept around the large chamber at the massed instrument panels that were recording every minute fraction of a second of the flight. And the glow grew. And suddenly the hissing of the exploding rocket fuel began to diminish in volume. The apex of the flight was nearly at hand then. And the glow around Gaddon began to color. From a weird phosphorescent whiteness it changed to a dull but intense yellow. And with the change, a strange feeling crept through his body. * * * * * It tugged at him with invisible hands. It played upon his every nerve, his every fiber, the innermost feelings of his sensibility. It grew stronger, this alien probing within him, grew as the glow pulsed in the chamber around him.