gave place to gravel.  Finally water welled in, a stronger volume than Cameron ever remembered finding on the desert.  It would soon fill the hole and run over.  He marveled at the circumstance.  The time was near the end of the dry season.  Perhaps an underground stream flowed from the range behind down to the valley floor, and at this point came near to the surface.  Cameron had heard of such desert miracles.

The finding of water revived Cameron’s flagging hopes.  But they were short-lived.  Warren had spend himself utterly.

“I’m done.  Don’t linger,” he whispered.  “My son, go—­go!”

Then he fell.  Cameron dragged him out of the sand pit to a sheltered place under the ledge.  While sitting beside the failing man Cameron discovered painted images on the wall.  Often in the desert he had found these evidences of a prehistoric people.  Then, from long habit, he picked up a piece of rock and examined it.  Its weight made him closely scrutinize it.  The color was a peculiar black.  He scraped through the black rust to find a piece of gold.  Around him lay scattered heaps of black pebbles and bits of black, weathered rock and pieces of broken ledge, and they showed gold.

“Warren!  Look!  See it!  Feel it!  Gold!”

But Warren had never cared, and now he was too blind to see.

“Go—­go!” he whispered.

Cameron gazed down the gray reaches of the forlorn valley, and something within him that was neither intelligence nor emotion—­something inscrutably strange—­impelled him to promise.

Then Cameron built up stone monuments to mark his gold strike.  That done, he tarried beside the unconscious Warren.  Moments passed—­grew into hours.  Cameron still had strength left to make an effort to get out of the desert.  But that same inscrutable something which had ordered his strange involuntary promise to Warren held him beside his fallen comrade.  He watched the white sun turn to gold, and then to red and sink behind mountains in the west.  Twilight stole into the arroyo.  It lingered, slowly turning to gloom.  The vault of blue black lightened to the blinking of stars.  Then fell the serene, silent, luminous desert night.

Cameron kept his vigil.  As the long hours wore on he felt creep over him the comforting sense that he need not forever fight sleep.  A wan glow flared behind the dark, uneven horizon, and a melancholy misshapen moon rose to make the white night one of shadows.  Absolute silence claimed the desert.  It was mute.  Then that inscrutable something breathed to him, telling him when he was alone.  He need not have looked at the dark, still face beside him.