He signaled the physicist. Lorre flipped the switch, gaining satisfaction from the humming drone that came from the generators. An instant later, they hit the Layer. Livid sheets of flame danced outside the portholes as the surging ions fought to break the shield that enveloped the ship with the intrepid band of spacefarers aboard. Could they cheat nature with their science? The hull began to grow hot. Lorre increased the power. [Illustration: _Lurid sheets of flame danced outside the portholes as the surging ions sought to break the shield._] Then they were through! The tremendous velocity gained before cutting the acceleration had carried them through! They were now in the star-specked blackness of outer space, their ionoscreen, which duplicated conditions in the H-layer, surrounding the craft at a safe distance. Apparently it was keeping the cosmic rays out as predicted. It had been done at last! Space travel was an accomplished thing. Mars, Venus, the Major Planets, all were within man's reach. It was the dawn of a new era! Hammond, the pilot, turned to congratulate the physicist who had made all this possible. But his grin faded, he raised his eyebrows in astonishment at what he saw. Lorre, having experienced the successful culmination of years of effort, lay on the floor of the control room, apparently fast asleep! That the polari-neutralizer would be a success, Lorre had felt certain. But he could not control the elation he felt as they passed the outer edge of the Layer. _He_ had made it possible! Someone whispered. The physicist looked at Hammond. The pilot was staring out the port. Then he heard it again. But this time it was--commanding! Commanding him to lie down! Lorre did so. He seemed unable to summon the will power to resist. The whisper went on. It seemed to be communicating directly with his mind, without the use of the indirect route through sense organs. When Lorre realized that the whisper began to form coherent words. He became oblivious to all else. Thus it was that when Hammond tore his gaze from the port, he found the physicist in a comatose condition. Rapidly, he summoned the rest of the crew. It consisted of--a doctor, a bio-chemist, a metallurgist, and a mechanic. They had been picked out of hundreds of volunteers. Able men, they were ready for any emergency that might arise. The doctor immediately tried to bring the seemingly unconscious man around. Lorre came to suddenly. "What's wrong?" he inquired of the doctor, who explained as much as he knew, which was little. "Of course," said Lorre. "I might have known." Then, "Hammond!" "Yes?" "Decelerate immediately. We must return to Earth as soon as possible." "But the moon?" "The moon is comparatively unimportant now. Besides, I can tell you exactly what we would find there. I'll explain everything as we go back. Start the generators. We must accumulate power to penetrate the H-layer on our return."