The lieutenant looked long and intently out over the dreary flats beyond the foot-hills.  Like the bottom of some prehistoric lake long since sucked dry by the action of the sun, the parched earth stretched away in mile after mile of monotonous, life-ridden desert, a Sahara without sign of an oasis, a sandy barren shunned even by scorpion and centipede.  Already the glow was dying from the western sky.  The red rim of the distant range was purpling.  The golden gleam that flashed from rock to rock as the sun went down had vanished from all but the loftiest summits, and deep, dark shadows were creeping slowly out across the plain.  Over the great expanse not so much as the faintest spark could be seen.  Aloft, the greater stars were beginning to peep through the veil of pallid blue, while over the distant pass the sun’s fair hand-maiden and train-bearer, with slow, stately mien, was sinking in the wake of her lord, as though following him to his rest.  Not a breath of air was astir.  The night came on still as the realms of solitude.  Only the low chatter of the men, the occasional stamp of iron-shod hoof or the munching jaws of the tired steeds broke in upon the perfect silence.  From their covert in the westward slope of the Christobal the two sentries of the little command looked out upon a lifeless world.  Beneath them, whiffing their pipes after their frugal supper, the troopers were chatting in low tone, some of them already spreading their blankets among the shelving rocks.  The embers from the cook fire glowed a deeper red as the darkness gathered in the pass, and every man seemed to start as though stung with sudden spur when sharp, quick, and imperative there came the cry from the lips of the farther sentry,—­

“Fire, sir,—­out to the west!”

In an instant Lieutenant Drummond had leaped down the rocky canon and, field-glass in hand, was standing by the sentry’s side.  No need to question “Where away?” Far out across the intervening plain a column of flame was darting upward, gaining force and volume with every moment.  The lieutenant never even paused to raise the glass to his eyes.  No magnifying power was needed to see the distant pyre; no prolonged search to tell him what was meant.  The troopers who had sprung to their feet and were already eagerly following turned short in their tracks at his first word.

“Saddle up, men.  It’s the beacon at Signal Peak.”

Then came a scene of bustle.  No words were spoken; no further orders given.  With the skill of long practice the men gathered their few belongings, shook out the dingy horse-blankets and then, carefully folding, laid them creaseless back of the gaunt withers of their faithful mounts.  The worn old saddles were deftly set, the crude buckles of the old days, long since replaced by cincha loop, snapped into place; lariats coiled and swung from the cantle-rings; dusty old bits and bridles adjusted; then came the slipping into carbine-slings and thimble-belts, the quick lacing of Indian moccasin or canvas legging, the filling of canteens in the tepid tanks below, while all the time the cooks and packers were flying about gathering up the pots and pans and storing rations, bags, and blankets on the roomy apparejos.  Drummond was in the act of swinging into saddle when his sergeant hastened up.