On reaching the hilly country Frank struck into a trail leading through a district that was rapidly growing wilder as they advanced; though after a while they might again strike out on the open country.
There were times when the trail itself was so narrow that Bob fell in behind, and they moved along in single file, the horses climbing the rise gallantly.
Frank had his eyes ahead. He fancied that he had detected some slight movement at a turn about fifty yards beyond the spot they had now reached.
“Hold up a minute, Bob!” he exclaimed, holding out his hand in the manner understood by every rider of the plains.
Just as he spoke he heard a strange “swishing” sound close by. Involuntarily Frank ducked his head. Brought up amid such surroundings, his ear was in tune with all things connected with range life; and in this hissing sound he knew that he had caught the whirl of a lariat through the air. Just as he turned in his saddle, he heard from his chum a half-muffled cry that thrilled him.
CHAPTER II
THE SUDDEN ALARM
When he turned so hastily, the astonished Frank was just in time to see his chum topple from his saddle, and fall heavily to the ground.
Domino, the black Kentucky horse, began plunging wildly; but, fortunately, Bob’s feet were free from the stirrups, so there was no danger of his being dragged, should the mettlesome horse bolt.
A series of yells broke forth from the rocks and bushes just above the road. It was from that point that the rope had been thrown which had caught Bob so neatly, and unseated him.
Filled with the greatest alarm, and half fancying that they had been waylaid by some Indians off their reservation, Frank was trying to get hold of his rifle, which he carried fastened to his back.