Another halt at sundown, a fairly good meal, and a refreshing sleep,
before the doctor roused all once more towards midnight for the tramp
that was to last till about ten o'clock the next day. All was done this
time in silence, save that Bourne tried to say hopefully--

"I should think we shall see the mountains quite clearly when day
dawns."

But no one answered, for nobody believed they would. A feeling of
despondency was making itself too plainly felt, and when broad daylight
did at last come all that could be seen was sand and soda everywhere,
not so much as a shrub or scrap of grass, only scattered stones here and
there, and the party shrank from looking in each other's wild and
bloodshot eyes.

"Forward," said the doctor, at last. "We'll keep on till about two
hours before noon, and then have a good meal and rest till the sun's
low. We must be getting well on to our journey's end."

About this time the doctor edged up close to Griggs and entered into
conversation with him in a low tone, "What do you think of it?" he said.

"Don't think at all, sir," was the reply.

"But we shall do it?"

"Must, sir."

"That's right," said the doctor, with a sigh of relief. "We must not
think, but we must do it. We've got over the worst of it now, I feel
sure."

The doctor was wrong, for there was an unexpected trouble ahead.

Towards the promised time for the halt there was what all took for a
more hopeful sign: the plain was growing more stony and undulatory,
while sage-brush peeped out in clumps here and there, to be gladly
welcomed by the animals, which lost not an opportunity of cropping the
bitter shoots.

The sun was getting hotter and hotter, and the doctor drew out his
watch, to close it again with a snap which sounded curiously loud in the
painful silence.

"Only another hour," he said, in a husky voice, "and then rest and
breakfast."

He had hardly uttered the words when one of the mules, which had broken
a little way from the line with outstretched muzzle, to nibble a few
grey twigs, gave a leap which nearly dislodged its pack, and uttering a
dismal squeal which was answered by two or three of its fellows, who
turned their weary, straining eyes towards their companion, which now
stood snorting and stamping angrily.

"What's the matter with the poor brute?" cried the doctor, who hurried
towards the animal, closely followed by Griggs.

"Take care, sir--that," said the latter, in a whisper.

"Th