zzling for Terran eyes the miniature sun swung out, not in
orbit but in straight line of flight, heading to their right.

With a muffled cry, Thorvald started in pursuit, Shann running beside
him. They were in a tunnel of the fog now, and the pace set by the
spinning coin was swift. The Terrans continued to follow it at the best
pace they could summon, having no idea of where they were headed, but
each with the hope that they finally did have a guide to lead them
through this place of confusion and into a sane world where they could
face on more equal terms those who had sent them there.

14. ESCAPE

"Something ahead!" Thorvald did not slacken the pace set by the
brilliant spot of green they trailed. Both of the Terrans feared to fall
behind, to lose touch with that guide. Their belief that somehow the
traveling disk would bring them to the end of the mist and its attendant
illusions had grown firmer with every foot of ground they traversed.

A dark, fixed point, now partly veiled by mist, lay beyond, and it was
toward that looming half-shadow that the spinning disk hurtled. Now the
mist curled away to display its bulk--larger, blacker and four or five
times Thorvald's height. Both men stopped short, for the disk no longer
played pathfinder. It still whirled on its axis in the air, faster and
faster, until it appeared to be throwing off sparks, but the sparks
faded against a monolith of dark rock unlike the native stone they had
seen elsewhere. For it was neither red nor warmly brown, but a dull,
dead black. It could have been a huge stone slab, trimmed, smoothed, set
up on end as a monument or marker, except that only infinite labor could
have accomplished such a task, and there was no valid reason for such
toil as far as the Terrans could perceive.

"This is it." Thorvald moved closer.

By the disk's action, they deduced that their guide had drawn them to
this featureless black steel with the precision of a beam-controlled
ship. However, the purpose still eluded them. They had hoped for some
exit from the territory of the veil, but now they faced a solid slab of
dark stone, neither a conventional exit or entrance, as they proved by
circling its base. Beneath their boots was the eternal sand, around
them the fog.

"Now what?" Shann asked. They had made their trip about the slab and
were back again where the disk whirled with unceasing vigor in a shower
of emerald sparks.

Thorvald shook his head, scann