"Ow, Wow, Wow, Wow Y-E-O-W " Tad Butler, who was industriously chopping wood at the rear of the woodshed of his home, finished the tough, knotted stick before looking up. The almost unearthly chorus of yells behind him had not even startled the boy or caused him to cease his efforts until he had completed what he had set out to do. This finished, Tad turned a smiling face to the three brown-faced young men who were regarding him solemnly.

"If this is the desert, then I think I prefer mountains," decided Stacy Brown. "It is not the desert. We have not reached it yet. This is the Diamond Range," replied Tom Parry, who was to guide the Pony Rider Boys across the great Nevada Desert. "We shall soon be there, however." "You'll know the place when you see it, Chunky," said Ned Rector. "And feel it, too, I guess," added Tad Butler under his breath. "We have the desert on each side of us now," continued the guide. "Were you to fire a rifle to the right or left, your bullet would fall on the baking alkali of the desert."

"What was that?" "Only one of the boys in the seat behind us, snoring." "Sure they're asleep?" "Yes, but what if they're not? They are only kids. They wouldn't understand." "Don't you be too sure about that. I've heard about those kids. Heard about 'em over in Nevada. There's four of them. They call themselves the Pony Rider Boys; and they're no tenderfeet, if all I hear is true. They have done some pretty lively stunts."

"Boys B-o-y-s " There was no response to the imperative summons. Professor Zepplin sat up in his cot, listening intently. Something had awakened him suddenly, but just what he was unable to decide. "Be quiet over there, young men," he admonished, adding in a lower tone, "I'm sure I heard some one moving about."