“It’s a wolf likely,” said Dick, but all three seized and cocked their rifles nevertheless.

Again Crusoe growled more angrily than before, and springing out of the camp snuffed the breeze anxiously.

“Up, lads! catch the nags!  There’s something in the wind, for the dog niver did that afore.”

In a few seconds the horses were saddled and the packs secured.

“Call in the dog,” whispered Joe Blunt; “if he barks they’ll find out our whereabouts.”

“Here, Crusoe, come—­”

It was too late; the dog barked loudly and savagely at the moment, and a troop of Indians came coursing over the plain.  On hearing the unwonted sound they wheeled directly and made for the camp.

“It’s a war party; fly, lads! nothin’ ’ll save our scalps now but our horses’ heels,” cried Joe.

In a moment they vaulted into the saddle and urged their steeds forward at the utmost speed.  The savages observed them, and with an exulting yell dashed after them.  Feeling that there was now no need of concealment, the three horsemen struck off into the open prairie, intending to depend entirely on the speed and stamina of their horses.  As we have before remarked, they were good ones; but the Indians soon proved that they were equally well if not better mounted.

“It’ll be a hard run,” said Joe in a low, muttering tone, and looking furtively over his shoulder.  “The varmints are mounted on wild horses—­leastways they were wild not long agone.  Them chaps can throw the lasso and trip a mustang as well as a Mexican.  Mind the badger-holes, Dick.—­Hold in a bit, Henri; yer nag don’t need drivin’; a foot in a hole just now would cost us our scalps.  Keep down by the creek, lads.”

“Ha! how dey yell,” said Henri in a savage tone, looking back, and shaking his rifle at them, an act that caused them to yell more fiercely than ever.  “Dis old pack-hoss give me moche trobel.”

The pace was now tremendous.  Pursuers and pursued rose and sank on the prairie billows as they swept along, till they came to what is termed a “dividing ridge,” which is a cross wave, as it were, that cuts the others in two, thus forming a continuous level.  Here they advanced more easily; but the advantage was equally shared with their pursuers, who continued the headlong pursuit with occasional yells, which served to show the fugitives that they at least did not gain ground.

A little to the right of the direction in which they were flying a blue line was seen on the horizon.  This indicated the existence of trees to Joe’s practised eyes, and feeling that if the horses broke down they could better make a last manful stand in the wood than on the plain he urged his steed towards it.  The savages noticed the movement at once, and uttered a yell of exultation, for they regarded it as an evidence that the fugitives doubted the strength of their horses.

“Ye haven’t got us yet,” muttered Joe, with a sardonic grin.  “If they get near us, Dick, keep yer eyes open an’ look out for yer neck, else they’ll drop a noose over it, they will, afore ye know they’re near, an’ haul ye off like a sack.”