descent began. Ten minutes later the entire party was back in the cavern.
The searchlights on the borer were switched on and Cliff gave brief instructions. Then while three men remained to watch the searchlights and guide them according to orders, the others went to work to examine the rocky walls of the place inch by inch. Ladders were set up against the approximate spot where the light had burned out Richardson's life.
Val and Cliff chose this particular task as their own especial duty. It took them some fifteen minutes of searching to discover a ball of anilum, only a small one, imbedded in the rock. In the center of the ball was curiously faceted lens.
"Looks like a glorified limelight,”" Val said, scratching his head. "Not a chance of moving it. Only thing to do is to avoid it."
"Yeah, I guess you're right—"
Cliff broke off with a start and turned round with dangerous speed on the ladder at a sudden wild scream from the opposite side of the cavern. He and Val were just in time to see part of the floor crack suddenly up the center in so neat a chasm that it was obviously mechanical. The floor simply fell apart in one complete seam—but into it dropped nearly thirty of the workers gathered in a bunch to inspect the giant ball. Their screams, mingled with the grinding roar of the floor's parting, filled the giant cavern with hideous commotion.
Cliff started to say something, then changed his mind. He scrambled down the ladder at top speed with Val tumbling after him. With the other workmen and scattered engineers they raced across in long leaps to the opening—but before they reached it it began to close with invincible power like the jaws of a mammoth press. The agonized cries from below lapsed abruptly into silence. With a mighty clang the metal floor linked up again, leaving a line so thin it was almost indetectable.
Cliff wiped his sweating face and looked around in bewilderment on his comrades' horrified faces.
"I don't begin to understand it," he almost whispered. "This is unthinkable! Ghastly! Thirty of them trapped down there and then crushed to death. . . . We've got to stop this if it's the last thing we ever do! You realize that, all of you?" he nearly shouted.
"Yeah, sure. Take it easy. It wasn't your fault." Val's voice was gruff with sympathy.
"Not my fault, perhaps, but I'm head of the Expedition and responsible for everybody here. Try to think how I feel . . ." Cliff knelt down and stared at the closed jaws of the floor. He got up with a hopeless look in his eyes. "No possible chance of doing anything until we smash open these damned anilum balls!" he blazed. "Get dynamite, tilanite, every damn thing! We'll blast this cavern wide open if we go to hell with it!"
Cliff twisted round sharply as Benson shouted hoarsely, "The air conditioning machine has stopped!"
"We've got our portable unit," Val said, relighting his pipe with feigned calmness. No time now to let panic gain a foothold. "Better get it, just in case we have trouble getting free."
Benson departed, and with him the men who were to bring the explosives. Cliff paced up and down swiftly, impatiently, watched by the other engineers. Most of them turned to look presently at the crack in the floor which had so ruthlessly swallowed up most of the party. They glanced uncertainly, furtively, around them, conscious of unseen but diabolical forces wailing to swallow them.
