And all unconscious of coming danger the boys rode with the few herders, or by themselves, near the wandering cattle.  The storm had held off while twilight faded, but now the sky was cloud-curtained, and the night fell inky black and silent save for sounds from the herd.  The soft thudding of hoofs, the occasional low-voiced note, possibly of a cow to its young, seemed to blend into a murmur, strange and fascinating to Whitey, commonplace and tiresome to the men of the range.

Then the storm began to send signals of its approach from air and sky.  First the hushing of the wind, then the pale glares from the distant sky where the earth’s edge joined it, then the rumble of thunder, growing in volume with the brighter, green flashes of the lightning—­all familiar enough to Whitey, but now giving him a thrill because felt in strange surroundings.  The nervous stirring of the mass of beasts near by added to the boy’s thrill, for a coming storm was never to be taken calmly by the hulking, helpless brutes.

And when the rush of wind and the crashing of the coming tempest sounded, and the herders were renewing their watchfulness, another storm was breeding that they did not dream of.  For over beyond, in a gully, the sheepmen were gathered.  And each man carried a white garment, like those you may have seen pictured as worn by the old raiders of the South—­the Ku-Klux Klan.  They were waiting only for the lightning to become blinding, the thunder to become deafening.

And when the electrical storm was at its height, you will know what happened when those white-clad figures went among the thousands of range-bred beasts, guarded by a pitiful handful of men.  For range cattle are accustomed to a man only when he is mounted; then he is a part of his horse.  It is dangerous for him to go among them on foot; then he is a strange animal.  Many a cowboy has dismounted, rescued a steer from the mire—­and had to run for his life.  Thus were those white-clad figures doubly monstrous and terrifying to the herd.

You may have thought that the cowboy wears his revolver for protection against his human enemies, but it is rather for a protection of the cattle against themselves in that strange panic known as a “stampede.”  Whitey and Injun, riding near the edge of the herd, and bowing against the fury of the storm, did not need Buck Milton’s hoarse shouts of warning to make them swing aside.  They were helpless to aid in diverting the mass of maddened animals that swung toward them, and galloping their horses to a point of safety, they turned in their saddles and viewed the strange sight.

Lighted by the almost continuous flashes of the lightning, the bellowing, thundering herd crashed by....  Far behind it, and in safety, were the white figures of the men who had caused the panic, sneaking off into the night.  They had been seen by the Star Circle riders, but there was no time to think of them now.  At the head of the herd, Whitey could see two men, their horses set at a mad run.  Buck Milton was one, and the other a dare-devil young fellow named Tom, who was Buck’s closest friend.