Shefford seemed to shut his eyes upon darkness and to open them immediately to the light.  The stream of blue sky above, the gold tints on the western rim, the rosy, brightening colors down in the canyon, were proofs of the sunrise.  This morning Nas Ta Bega proceeded leisurely, and his manner was comforting.  When all was in readiness for a start he gave the mustang he had ridden to Shefford, and walked, leading the pack-animal.

The mode of travel here was a selection of the best levels, the best places to cross the brook, the best banks to climb, and it was a process of continual repetition.  As the Indian picked out the course and the mustangs followed his lead there was nothing for Shefford to do but take his choice between reflection that seemed predisposed toward gloom and an absorption in the beauty, color, wildness, and changing character of Nonnezoshe Boco.

Assuredly his experience in the desert did not count in it a trip down into a strange, beautiful, lost canyon such as this.  It did not widen, though the walls grew higher.  They began to lean and bulge, and the narrow strip of sky above resembled a flowing blue river.  Huge caverns had been hollowed out by some work of nature, what, he could not tell, though he was sure it could not have been wind.  And when the brook ran close under one of these overhanging places the running water made a singular, indescribable sound.  A crack from a hoof on a stone rang like a hollow bell and echoed from wall to wall.  And the croak of a frog—­the only living creature he had so far noted in the canyon—­was a weird and melancholy thing.

Fay rode close to him, and his heart seemed to rejoice when she spoke, when she showed how she wanted to be near him, yet, try as he might, he could not respond.  His speech to her—­what little there was—­did not come spontaneously.  And he suffered a remorse that he could not be honestly natural to her.  Then he would drive away the encroaching gloom, trusting that a little time would dispel it.

“We are deeper down than Surprise Valley,” said Fay.

“How do you know?” he asked.

“Here are the pink and yellow sago-lilies.  You remember we went once to find the white ones?  I have found white lilies in Surprise Valley, but never any pink or yellow.”

Shefford had seen flowers all along the green banks, but he had not marked the lilies.  Here he dismounted and gathered several.  They were larger than the white ones of higher altitudes, of the same exquisite beauty and fragility, of such rare pink and yellow hues as he had never seen.  He gave the flowers to Fay.

“They bloom only where it’s always summer,” she said.