Wayland glanced back. The heavy dust rose a red-black curtain above the flame-crested ridges of orange sand.
"You're a churchman, sir! You should know! Ever read in Scripture of the cloud by day and the pillar by night? Ever think what that might mean on the scorching Red Sea job when Moses led a personally conducted tour through the desert?"
"Dust?" queried the preacher.
"By Harry," cried Wayland, "that mule does smell water."
The little beast had set off for the red rock at a canter. Wayland's horse followed at a long gallop. The broncho of the old clergyman with the heavier man lurched to a tired lope. They felt the eddies of dust as they tore ahead, saw the rainless clouds gathering low and gray far behind, saw the sun lurid through the whirls of red silt, saw the dust toss up among the lava beds like snow in a blizzard, then the sand storm broke, the dry storm of rainless clouds and choking dust flaying the air in rainless lightning. They gave the ponies blind rein and shot round the sheltered side of the great red rock into one of those hidden river beds that trench below the surface of the desert in cutways and canyons. It was dry.
"The shadow of a great rock in a weary land," quoted the old man sliding from his horse exhausted.
Foot prints of men and horses punctured the moist silt of the river bottom. The little mule was kicking and squealing where the red rock came through the clay bank. Down the terra cotta ledge trickled a tiny rill not so large as a pencil. Wayland was chopping a deep mud hole in the river-bottom up which slowly oozed a yellow pool.
"Don't drink that, sir," he ordered.
The old frontiersman was stooping to lave up a handful of the muddy fluid.
"Don't drink that if you want to get out alive! Wait, I have something in the pack!"