Shefford bade Nonnezoshe a mute, reverent farewell.  Then plunging down the weathered slope of the gorge to the stream below, he hurried forward to join the others.  They had progressed much farther than he imagined they would have, and this was owing to the fact that the floor of the gorge afforded easy travel.  It was gravel on rock bottom, tortuous, but open, with infrequent and shallow downward steps.  The stream did not now rush and boil along and tumble over rock-encumbered ledges.  In corners the water collected in round, green, eddying pools.  There were patches of grass and willows and mounds of moss.  Shefford’s surprise equaled his relief, for he believed that the violent descent of Nonnezoshe Boco had been passed.  Any turn now, he imagined, might bring the party out upon the river.  When he caught up with them he imparted this conviction, which was received with cheer.  The hopes of all, except the Indian, seemed mounting; and if he ever hoped or despaired it was never manifest.

Shefford’s anticipation, however, was not soon realized.  The fugitives traveled miles farther down Nonnezoshe Boco, and the only changes were that the walls of the lower gorge heightened and merged into those above and that these upper ones towered ever loftier.  Shefford had to throw his head straight back to look up at the rims, and the narrow strip of sky was now indeed a flowing stream of blue.

Difficult steps were met, too, yet nothing compared to those of the upper canyon.  Shefford calculated that this day’s travel had advanced several hours; and more than ever now he was anticipating the mouth of Nonnezoshe Boco.  Still another hour went by.  And then came striking changes.  The canyon narrowed till the walls were scarcely twenty paces apart; the color of stone grew dark red above and black down low; the light of day became shadowed, and the floor was a level, gravelly, winding lane, with the stream meandering slowly and silently.

Suddenly the Indian halted.  He turned his ear down the canyon lane.  He had heard something.  The others grouped round him, but did not hear a sound except the soft flow of water and the heave of the mustangs.  Then the Indian went on.  Presently he halted again.  And again he listened.  This time he threw up his head and upon his dark face shone a light which might have been pride.

“Tse ko-n-tsa-igi,” he said.

The others could not understand, but they were impressed.

“Shore he means somethin’ big,” drawled Lassiter.

“Oh, what did he say?” queried Fay in eagerness.

“Nas Ta Bega, tell us,” said Shefford.  “We are full of hope.”

“Grand Canyon,” replied the Indian.

“How do you know?” asked Shefford.

“I hear the roar of the river.”

But Shefford, listen as he might, could not hear it.  They traveled on, winding down the wonderful lane.  Every once in a while Shefford lagged behind, let the others pass out of hearing, and then he listened.  At last he was rewarded.  Low and deep, dull and strange, with some quality to incite dread, came a roar.  Thereafter, at intervals, usually at turns in the canyon, and when a faint stir of warm air fanned his cheeks, he heard the sound, growing clearer and louder.