“Now, Ned,” he said, “you and I cannot go forever without sleep.  We’ve been through a good deal and we haven’t closed our eyes for thirty-six hours.  I feel as if I had pound weights tied to my eyelids.”

“Two-pound weights are tied to mine.”

“Then we’ll prove the value of my foresight in obtaining the two sets of blankets by using them at once.”

Each lay down between his blankets, and Ned was soon asleep, but Obed, by a violent effort, kept his eyes open.  He could never remember a time when it seemed sweeter to sleep, but he struggled continually against it.  When he saw that Ned’s slumber was deep he rose and walked up and down the stream again, going a half mile in either direction.

At one point where there was a break in the fringe of trees the imprints of the mighty hoofs were numerous, and, mingled with them, were tracks made by horses’ hoofs.  It was these that worried Obed so much.  They were made by unshod hoofs, but evidently they were two or three days old, and, after all, the riders might have passed on, not to return.  Smothering his anxiety as much as possible he went back to their little camp, crept between his two blankets which felt very warm, and began to watch with his eyes and ears, vowing to himself that he would not sleep.

Yet within two hours he slept.  Exhausted nature triumphed over will and claimed her own.  He was not conscious of any struggle.  He was awake and then he was not.  The two tethered horses, having eaten all they wanted, also settled themselves comfortably and slept.

But while the two, or rather the four slept, something was moving far out on the plain.

It was an immense black mass with a front of more than a mile, and it was coming toward Ned and Obed.  This mass had been disturbed by a great danger and it advanced with mighty heavings and tramplings.  Ned and Obed slept calmly for a long time, but as the black front of the moving mass drew closer to the creek and its thin lines of trees, the boy stirred in his blankets.  A vague dream came and then a state that was half an awakening.  He was conscious in a dim way of a low, thundering sound that approached and he sprang to his feet.  The next instant a neigh of terror came from one of the horses and Obed, too, awoke.

“Listen!” exclaimed Ned.  “Hear that roar!  And it’s drawing near, too!”

“Yes, it’s a buffalo herd!” said Obed.  “We’re far enough north now to be within the buffalo ranges, and they’re coming down on us fast.  But they must be scared or be drawn on by something, because it’s not yet dawn.”

“All of which means that it’s time for us to go.”

“Or be trodden to death.”

Naturally, they had slept in their clothes and they quickly gathered up their arms and baggage.  Then they released their frightened horses, sprang upon their backs and galloped toward the north.  They felt secure now, so far as the herd was concerned.  Their horses could easily take them out of its reach.