Once the boys came unexpectedly on a buffalo bull also standing knee-deep in the river, drinking his fill, or cooling off after a warm day. And Roger, being quick to act, had fired his feathered barb almost before Dick could warn him to be careful. The result was that the wounded beast charged the boat, and upset it, so that the boys were given wet jackets, and might have even suffered the loss of their long-barreled guns only that they had the good sense to keep a tight grip on these as they floundered in the water. The enraged and wounded buffalo was ready to attack them again, and so Dick, in order to settle the matter in their favor, was compelled to make use of his rifle, shooting the bull at close quarters, just as he was rushing toward the spot where Roger was splashing in his endeavor to keep his head above the surface. It can be understood that after such an experience Roger was apt to stay his hand whenever it happened that they discovered a buffalo in the river; since another time they might not chance to be so fortunate. So the days passed, and the pioneer boys were enjoying themselves vastly; but the time came when the peaceful scene was suddenly changed. There seemed to be a commotion ahead, and the boys, who had been riding in the rear, galloped up in order to learn what it all meant. Some of the scouts had come in to announce that they were now drawing close to the Mandan village, where Captain Lewis was thinking of settling down for the autumn and winter, if the signs were favorable. This meant, if he could make the chief a good friend by the bestowal of presents, such as looking-glasses, beads, knives, and other things kept in stock for this very purpose. "To-morrow, they say, we ought to be there," Roger told Dick, as they rode on. "Yes, and oh! how I hope that we will find Jasper Williams waiting for the expedition to arrive," returned Dick, with considerable emotion; for the longer this meeting was delayed, the more it began to get upon their nerves. "Well," remarked Roger, turning philosopher for once, "we've been so lucky up to now that I don't see how we could miss getting his signature to that paper. He must be in the Mandan village; and by to-morrow night we may have had the two captains witness the signing of his name, that will mean so much to all at home." "You're right, Roger, and I believe the same, deep in my heart," Dick went on. "And, even if he should be away when we get to the Mandan village, it can only be for a short time. We will find him, believe that, if we have to go out after him." All that evening they were rather silent. The near approach of the crisis in their affairs rather appalled the lads. They had anticipated this thing for so long a time, that the coming of the fateful hour, when all must be put to the test, rather unnerved them.