hear it. Apparently, your voices are supersonic to
them."

"Well, I'll be fried," said Dodeth. He looked at the Elder Keeper.
"That's why the robots reported they couldn't find any _animal_ of
that description in the vicinity."

"Certainly. There weren't any."

"And we were so fooled by their monstrous appearance that we didn't
pay any attention to their actions," said Dodeth.

"Exactly."

"But this makes the puzzle even _worse_," said Dodeth. "How could such
a creature evolve?"

"Look!" interrupted one of the other Keepers, pointing. "Up there in
the sky!"

All eyes turned toward the direction the finger pointed.

It was a silvery speck in the sky that moved and became larger.

"I don't think they're from our World at all," said the Eldest Keeper.
He turned to the patrol robot. "Arvam, go down and tell the pesticide
robots that there is no danger to us. They're still confused, and I
have a feeling that the humans in that ship up there might not like it
if we are caught pointing guns at their friends."

As Arvam rolled off, Dodeth said "Another World?"

"Why not?" asked the Eldest. "The Moon, after all, is another World,
smaller than ours, to be sure, and airless, but still another World.
We haven't thought too much about other Worlds because we have our own
World to take care of. But there was a time, back in the days of the
builders of the surface cities, when our people dreamed such things.
But our Moon was the only one close enough, and there was no point in
going to a place which is even more hellish than our Brightside.

"But suppose the Yellow Sun also has a planet--or maybe even one of
the more distant suns, which are hardly more than glimmers of light.
They came, and they landed a few of their party to make a small
clearing. Then the ship went somewhere else--to the dark side of our
Moon, maybe, I don't know. But they were within calling range, for the
ship was called as soon as trouble appeared.

"We don't know anything about them yet, but we will. And we've got to
show them that we, too, are human. We have a job ahead of us--a job of
communication.

"But we also have a great future if we handle things right."

Dodeth watched the ship, now grown to a silvery globe of tremendous
size, drift slowly downward toward the clearing. He felt an inward
glow of intense anticipation, and he fidgeted impatiently as he waited
to see what would happen next.

He rippled a stomp.

THE END

*