But a few of them retained their inner life-force! They came surging forward. Curt threw up the radiant-rifle, spread a swath of disintegrant power that sent them buffeting back. Gradually they blanked out, until nothing moved in the length of corridor. The Zemmd's men had long since vanished from the scene. * * * * * It was over in minutes. Behind Curt came a harsh roar, then a crash of tubes and metal as the Tele-Magnum failed under the overload of power. But Tor still sang. Curt stepped warily forward, touched one of the grayish translucent shapes. It was warm. A decided shock, more than electrical, went through his arm. "These things aren't finished yet! We've got to hurry!" He stared at Lorine. "What happened to Jeffers?" She shook her head. Horror was still mirrored on her face. But Jeffers was gone! Somehow he had managed to make his way out! All weariness vanished, as Curt raced back through the corridors with Lorine hurrying after him. He had a chill premonition of what Jeffers was up to! A deathly silence settled over them. Tor's singing had stopped. Not until they reached the lifts did Curt notice that Tor had caught up with them. The little Martian was deathly pale but his eyes fever-bright, as he shook his head drunkenly and clutched at his throat. Curt paid him no heed now. They tumbled into one of the cars. A propulsion beam hummed, and they rose swiftly toward the upper compound. Jeffers was there, battling his way past a score of the Zemmd's men. But there was a great difference in these men now. They seemed disorganized and aimless without the co-ordinating, driving power of the Zemmd! Jeffers was heading toward a hangar-like building. The spaceship with the Frequency Tuner! The man's scheme was obvious now; he had given up on Lorine, decided to try it alone! Curt hurled himself forward, and a path opened for him as the men scurried to cover before the blast of the radiant-rifle. At all costs he must reach Jeffers-- He was too late. Already Jeffers had reached the building fifty yards away. He fumbled at the door, then disappeared. Curt was there seconds later. A gorge of despair rose in him, as he found the door barred from the inside. There might still be time! Jeffers would have to find the secret of the Electronic Curtain reaching above them. Frantically, Curt blasted at the door. The metal resisted stubbornly, but gradually it began to melt away. Then, from within, came a smooth droning sound. It increased in tempo. The building trembled against the full reverberant power. The Frequency Tuner! Jeffers was going to try to drive _through_ the Electronic Curtain. Curt realized his danger, and whirled away. The building smashed apart like an eggshell, hurling debris in all directions. Curt plummeted forward, caught a glimpse of the silver spacer streaking obliquely up on the whining power of the Tuner....