"... And this time, of course, I will keep the top disintegrators on. No other monster will then be able to weigh me down!"

He shrugged his shoulders and turned to the door. And that movement was the signal that brought his doom. Without a sound, the poised mass above dropped.

James Quade never knew what hit him. The heap of whitish jelly fell squarely. There was a brief moment of frantic lashing, of tortured struggles—then only tiny ripples running through the monster as it fed.

Sue Guinness turned her head. But the two men for some reason could not take their eyes away....


t was the girl's voice that jerked them back to reality. "The other!" she gasped. "It's coming, behind!"

They had completely forgotten the mass in the tunnel. Turning, they saw that it was only fifteen feet away and approaching fast, and instinctively they ran out into the cavern, skirting the sphere widely. When they came to Quade's wrecked borer Phil, who had snatched a glance behind, dragged them down behind it. For he had seen their pursuer abandon the chase and go to share in the meal of its fellow.

"We'd best not get too far away," he whispered. "When they leave the front of the borer, maybe we can make a dash for it."

For minutes that went like hours the young man watched, waiting for the creatures to be done, hoping that they would go away. Fortunately the sphere lay between, and he was not forced to see too much. Only one portion of one of the monsters was visible, lapping out from behind the machine....