The explanation of this sudden change in our hero's fortunes and prospects is that, while the Cheyennes were engaged in their buffalo-hunt the evening before, they had been discovered by a Pawnee scout. He was attached to a company of cavalry who were on their way back to Fort Hayes, on the Smoky Hill, from an expedition against the Arrapahoes. The captain of this company had determined to surprise the Indians thus unexpectedly thrown in his way, at daybreak, and had made his arrangements accordingly. Their movements had been carefully noted by the scouts, and, having made a start from their own camp at three o'clock that morning, the troops were cautiously surrounding the place where they supposed their sleeping foes to be.