"Yes; let's push on; we must lose no time."
Brinton longed to force the animals into a gallop, but dared not, after what had just taken place. But they were pushed to a rapid walk, which was kept up some ten or fifteen minutes, when came another sudden halt, for the good reason that they had reached the end of the arroya.
That singular formation, after winding about for a long distance, rose to the level of the prairie, and disappeared.
To proceed further must be done by exposure to any hostiles in the neighbourhood. Brinton stopped and looked inquiringly at his father.
"As near as I can judge," said the latter, "we are close to the Big Cheyenne; we ought to cross that early this evening and keep on to the White, which should be reached by daylight; then the ride is not far to Pine Ridge."
"Night is near; we will wait awhile; the rest will do you good, and I will take a look over our own trail."
Leaving his friends to themselves, Brinton headed back and struck Jack into a moderate gallop through the arroya.
He was uneasy over that accident with his father's Winchester. If heard by the keen-eared hostiles they would start an investigation, which could have but one result.
"They must have heard it," was his belief, "and if so, they knew where it came from. It won't take them long to learn its meaning—halloa! what's the matter, Jack?"
More than once, the sagacity of his animal had warned the youth of the approach of danger. The pony dropped into a walk so quickly that the rider was thrown slightly forward in the saddle. Then the animal pricked up his ears, took a few more stops and halted.