ween 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