By this time the sounds had grown quite loud, and both boys strained their eyes, trying to locate the approaching horsemen. In the old days on the plains every stranger was deemed an enemy until he had proven himself a friend. Nowadays it is hardly so positive as that; but nevertheless those who are wise take no chances.
"I see them!" Bob announced; but although the other saddle boy had not said so, he had picked up the advancing figures several seconds before.
"One thing sure," remarked Frank, as though relieved, "I reckon they can't be horse thieves or cattle rustlers."
"You mean they wouldn't be so bold about coming forward?" ventured Bob.
"That's about the size of it; but we'll soon know," Frank went on.
As the strangers drew rapidly nearer he began to make out their "style" for the night was not intensely dark. And somehow Frank's curiosity increased in bounds. He discovered no signs of the customary cowboy outfit about them. They wore garments that savored of civilization, and sat their horses with the air of men accustomed to much riding.
"Hold hard there, strangers; or you'll be riding us down!" Frank sang out, as the newcomers loomed up close at hand.
At that the others drew rein, and brought their horses to a halt. Bending low in the saddle they seemed to be peering at the dimly-seen figures of the two boys.
"Who is it—speak quick!" one of the strangers said; and Frank believed he heard a suspicious click accompanying the thrilling words.