ing the rock face before them glumly. The
eagerness had gone out of his expression, a vast weariness replacing it.

"There must have been some purpose in coming here," he replied, but his
tone had lost the assurance of moments earlier.

"Well, if we strike away from here, we'll just get right back in again."
Shann waved a hand toward the mist, waiting as if with a hunter's watch
upon them. "And we certainly can't go down." He dug a boot toe into the
sand to demonstrate the folly of that. "So, what about up?"

He ducked under the spinning disk to lay his hands against the surface
of the giant slab. And in so doing he made a discovery, revealed to his
touch although hidden from sight. For his fingers, running aimlessly
across the cold, slightly uneven surface of the stone, slipped into a
hollow, quite a deep hollow.

Excited, half fearing that his sudden guess might be wrong, Shann slid
his hand higher in line with that hollow, to discover a second. The
first had been level with his chest, the second perhaps eighteen inches
or so above. He jumped, to draw his fingers down the rock, with damage
to his nails but getting his proof. There _was_ a third niche, deep
enough to hold more than just the toe of a boot, and a fourth above
that....

"We've a ladder of sorts here," he reported. Without waiting for any
answer from Thorvald, Shann began to climb. The holds were so well
matched in shape and size that he was sure they could not be natural;
they had been bored there for use--the use to which he was now putting
them--a ladder to the top of the slab. Though what he might find there
was beyond his power to imagine.

The disk did not rise. Shann passed that core of light, climbing above
it into the greater gloom. But the holes did not fail him; each was
waiting in a direct line with its companion. And to an active man the
scramble was not difficult. He reached the summit, glanced around, and
made a quick grab for a secure handhold.

Waiting for him was no level platform such as he had confidently
expected to find. The surface up which he had just made his way
fly-fashion was the outer wall of a well or chimney. He looked down now
into a pit where black nothingness began within a yard of the top, for
the radiance of the mist did not penetrate far into that descent.

Shann fought an attack of giddiness. It would be very easy to lose
control, to tumble over and be swallowed up in what might well be a
bottomless chasm. And