"There may easily be," the scientist replied promptly. "But since the only defense against them is this one metal rod, I recommend that we leave our unfortunate comrades here and head immediately for the mountains over there. Those poor fellows are beyond our help and we should be able to find better protection from these blood-thirsty thorn-bushes among the foot hills. When we get there we can work upwind until we're opposite the Carrier again." "That sounds like good advice," said Dynamon. "And we'll act on it. It's getting so dark now that we couldn't see to protect ourselves if any more of those creatures came rolling down the wind. Everyone join hands and follow me." * * * * * After a nerve-racking march of about twenty-five minutes through the gathering darkness, the party of nine humans felt the ground rising beneath their feet. Dynamon halted and hurled a voltage bomb forward and upward. As the bomb exploded, the momentary flash revealed to the party that they were at the foot of a steep, rock-strewn declivity. Dynamon led the party upward, feeling his way over the great boulders. After a few minutes of climbing, he called another halt and again threw a voltage bomb. "We'll stay here for a few hours," the centurion announced, "until it gets light enough to see our way. We will be safe in the lee of these big rocks, so make yourselves comfortable." Nine dim figures spread out on the sloping ground. Then one of them drifted apart from the rest, up hill. "Who is that?" Dynamon demanded. "Keltry," came the answer. "I am just going up hill a little distance. When you exploded that last bomb I thought I saw something that looked like the edge of a volcanic crater." "You can't see anything in this darkness," said Dynamon. "Wait till it gets light again before you do any exploring." "Oh, I won't go far," said Keltry. "Really, I won't." "Well, be sure that you don't," Dynamon smiled into his transmitter. Then he said, "Thamon, where are you?" "Right here," and a figure moved over beside the centurion. Dynamon's question was casual. "Did you see anything that looked like a volcanic crater?" "Come to think of it," the scientist replied, "I think I did. It's just up here a few yards." "Shall we go along and have a look at it too, then?" said Dynamon, getting up on his feet. Just then, he stood rooted with horror as a piercing scream rang in his ear phone. "Dynamon! Dynamon, I'm falling!" "Keltry!" the centurion exclaimed. "What's the matter? Has something happened to your helmet?" "Yes!" Keltry's voice was fainter. "I've lost it! It was unfastened, and when I stumbled, it rolled off!" Fainter and fainter grew the voice. "I'm falling down a black hole a mile a minute!" With a muttered sob, Dynamon scrambled up the slope. A moment later, his foot stepped out on empty space. He started to fall into nothingness. "Keltry!" he cried into his transmitter. "Where are you? Answer me!"