lready vanished. The murk above them was less solid, but
again the fine grit streaked their faces, embedding itself in their
hair.

Shann paused to scrape a film of mud from his lips and chin. Then he
made the last pull, bracing his slight body against the push of the wind
he met there. A palm struck hard between his shoulders, nearly sending
him sprawling. He had only wits enough left to recognize that as an
order to get on, and he staggered ahead until rock arched over him and
the sand drift was shut off.

His shoulder met solid stone, and having rubbed the sand from his eyes,
Shann realized he was in a pocket in the cliff walls. Well overhead he
caught a glimpse of natural amber sky through a slit, but here was a
twilight which thickened into complete darkness.

There was no sign of wolverines. Thorvald moved along the pocket
southward, and Shann followed him. Once more they faced a dead end. For
the crevice, with the sheer descent to the river on the right, the cliff
wall at its back, came to an abrupt stop in a drop which caught at
Shann's stomach when he ventured to look down.

If some battleship of the interstellar fleet had aimed a force beam
across the mountains of Warlock, cutting down to what lay under the
first envelope of planet-skin, perhaps the resulting wound might have
resembled that slash. What had caused such a break between the height on
which they stood and the much taller peak beyond, Shann could not guess.
But it must have been a cataclysm of spectacular dimensions. There was
certainly no descending to the bottom of that cut and reclimbing the
rock face on the other side. The fugitives would either have to return
to the river with all its ominous warnings of trouble to come, or find
some other path across that gap which now provided such an effective
barrier to the west.

"Down!" Just as Thorvald had pushed him out of the murk of the dust
storm into the crevice, so now did that officer jerk Shann from his
feet, forcing him to the floor of the half cave from which they had
partially emerged.

A shadow moved across the bright band of sunlit sky.

"Back!" Thorvald caught at Shann again, his greater strength prevailing
as he literally dragged the younger man into the dusk of the crevice.
And he did not pause, nor allow Shann to do so, even when they were well
undercover again. At last they reached the dark hole in the southern
wall which they had passed earlier. And a push from Thorvald sent h