The flower-scented breeze and the rumbling of the river persisted long after the valley lay behind and above, but these failed at length in the close air of the huge abutting walls.  The light grew thick, the stones cracked like deep bell-strokes; the voices of man and girl had a hollow sound and echo.  Silvermane clattered down the easy trail at a gait which urged Hare now and then from walk to run.  Soon the gully opened out upon a plateau through the centre of which, in a black gulf, wound the red Colorado, sullen-voiced, booming, never silent nor restful.  Here were distances by which Hare could begin to comprehend the immensity of the canyon, and he felt lost among the great terraces leading up to mesas that dwarfed the Echo Cliffs.  All was bare rock of many hues burning under the sun.

“Jack, this is mescal,” said the girl, pointing to some towering plants.

All over the sunny slopes cacti lifted slender shafts, unfolding in spiral leaves as they shot upward and bursting at the top into plumes of yellow flowers.  The blossoming stalks waved in the wind, and black bees circled round them.

“Mescal, I’ve always wanted to see the Flower of the Desert from which you’re named.  It’s beautiful.”

Hare broke a dead stalk of the cactus and was put to instant flight by a stream of bees pouring with angry buzz from the hollow centre.  Two big fellows were so persistent that he had to beat them off with his hat.

“You shouldn’t despoil their homes,” said Mescal, with a peal of laughter.

“I’ll break another stalk and get stung, if you’ll laugh again,” replied Hare.

They traversed the remaining slope of the plateau, and entering the head of a ravine, descended a steep cleft of flinty rock, rock so hard that Silvermane’s iron hoofs not so much as scratched it.  Then reaching a level, they passed out to rounded sand and the river.

“It’s a little high,” said Hare dubiously.  “Mescal, I don’t like the looks of those rapids.”

Only a few hundred rods of the river could be seen.  In front of Hare the current was swift but not broken.  Above, where the canyon turned, the river sheered out with a majestic roll and falling in a wide smooth curve suddenly narrowed into a leaping crest of reddish waves.  Below Hare was a smaller rapid where the broken water turned toward the nearer side of the river, but with an accompaniment of twisting swirls and vicious waves.

“I guess we’d better risk it,” said Hare, grimly recalling the hot rock, the sand, and lava of the desert.

“It’s safe, if Silvermane is a good swimmer,” replied Mescal.  “We can take the river above and cut across so the current will help.”

“Silvermane loves the water.  He’ll make this crossing easily.  But he can’t carry us both, and it’s impossible to make two trips.  I’ll have to swim.”

Without wasting more words and time over a task which would only grow more formidable with every look and thought, Hare led Silvermane up the sand-bar to its limit.  He removed his coat and strapped it behind the saddle; his belt and revolver and boots he hung over the pommel.