Early upon the morning of the fourth day of their journey the travellers noted that the plain began to rise and sink in longer waves. Presently they found themselves approaching a series of rude and wild-looking hills of sand, among which they wound deviously as they might, confronted often by forbidding buttes and lofty dunes whose only sign of vegetation was displayed in a ragged fringe of grass which waved like a scalp lock here and there upon the summits. For many miles they travelled through this difficult and cheerless region, the horses soon showing signs of distress and all the party feeling need of water, of which the supply had been exhausted. It was nearly noon while they were still involved in this perplexing region, and as none of the party had ever seen the country before, none could tell how long it might be before they would emerge from it. They pushed on in silence, intent upon what might be ahead, so that when there came an exclamation from the half-witted Mexican, whose stolid silence under most circumstances had become a proverb among them, each face was at once turned toward him. "Eh, what's that, Juan?" said Curly--"Say, boys, he says we're about out of the sand hills. Prairie pretty soon now, he says." "And will ye tell me, now," said Battersleigh, "how the haythen knows a bit more of it than we oursilves? He's never been here before. I'm thinkin' it's pure guess he's givin' us, me boy." "No, sir," said Curly, positively. "If Juan says a thing like that, he knows. I don't know how he knows it, but he shore does, and I'll gamble on him every time. You see, he ain't hardly like folks, that feller. He's more like a critter. He knows a heap of things that you and me don't." "That's curious," said Franklin. "How do you account for it?" "Kin savvy," said Curly. "I don't try to account for it, me. I only know it's so. You see if it ain't." And so it was. The wall of the sand hills was for a time apparently as endless and impervious as ever, and they still travelled on in silence, the Mexican making no further sign of interest. Yet presently the procession of the sand dunes began to show gaps and open places. The hills grew less tall and more regular of outline. Finally they shrank and fell away, giving place again to the long roll of the prairie, across which, and near at hand to the edge of the sand hills, there cut the open and flat bed of a water way, now apparently quite dry. "We're all right for water now," said Sam. "See that little pile of rocks, 'bout as high as your head, off to the right down the creek? That's water there, sure." "Yep," said Curly. "She's there, sure. Or you could git it by diggin' anywheres in here in the creek bed, inside of four or five feet at most."