vanished in thin air. And then, from somewhere off in the
emptiness of space above them, there came the sound of a deep and
mocking laughter!

* * * * *

As though that first laugh had somehow eased the necessity for a
carefully enforced silence, there came a whole burst of unseen and eerie
merriment. There was a murmur of many voices. Then it died away again.
There was still nothing visible, and the silence was once more unbroken.

"For Lord's sake, let's get out of here!" Portok gasped. "This place is
ghost ridden!"

"There are no ghosts here, little red-faced man!" boomed a voice.

The sound had seemed to come from somewhere overhead. From the empty
void above, where there was nothing at all until the cloud canopy was
reached many thousands of feet up. One of the _Viking's_ crew bared his
teeth in a sudden panic and lifted his ray-gun to fire blindly upward.
Before he could pull the trigger there was a blinding blue flash and a
crash like summer thunder. Captive lightning! The ray-gun flew from the
man's hands and landed a few feet away, its wooden stock badly charred
and its barrel a glowing mass of fused metal.

"Let your weapons rest, for they are useless here!" commanded that same
booming voice from above. "Whence came ye, strangers in odd clothing who
have traveled in a ship like a blue whale? What do ye seek here in the
Outer Isles?"

Gerry stepped forward, a few feet ahead of the group. He shouted that
they were a scientific exploring party who had come from Earth in a
space-ship. There was a brief period of silence, as though men consulted
in whispers. Then the voice called him again.

"You there--the leader! The Council of Elders will talk with you. Go
fifty paces to your right, to where there are two white stones, and then
come forward between them. Do not be afraid. You will not be harmed."

"Are you going to take the chance, Chief?" Steve whispered. Gerry
nodded.

"I'll have to."

About fifty yards to his right Gerry saw two white stones. They were set
some twelve or fifteen feet apart, on the very edge of the invisible
barrier. Gerry walked over, turned left, and then walked squarely in
between the stones. He held one arm protectingly in front of him, but
this time his hand did not encounter any barrier. Instead--he found
himself standing under the arch-way of a gate with a mighty city spread
before him!

* * * * *

The city h