Possibly he may have supposed that it was only a visit from some of the Mandans on an errand connected with their now friendly association with the whites. Then again, the commander may have wondered whether one of the hunting parties had arrived with some unusual species of game, such as none of the explorers had ever seen before. When, after striding forward to join the crowd, he saw the dusty messenger, a frown came upon his ordinarily pleasant face. Captain Lewis knew that something must have gone amiss, or the man who, with two companions, had started over the back trail several days before would not have returned to camp in this way. "What does this mean, Mayhew?" he demanded, as he came up, the others parting to allow a free passage, though naturally the two boys stuck to their posts, because they had an especial interest in whatever story the returned messenger might be about to relate. "Something has happened, Captain Lewis, I'm sorry to tell you, and not at all to my credit," replied the man, trying to calm himself, though it was evident that he was laboring under great stress of emotion. "Were you attacked on the way?" asked the President's private secretary, who had been entrusted with most of the responsibility of the excursion, and therefore felt more keenly than any one else the possibility of failure. He had taken great pains to keep a daily account of the trip up to that point, and this diary he had sent to the head of the Government in the care of the three men, one of whom now stood before him with dejected mien. "We believed we had taken all ordinary precautions, Captain," the messenger continued, making a brave effort to confess his fault as became a man; "but, in the darkness of the night, they crept upon us without any one being the wiser. My horse gave the alarm with a whinny, and, as I awoke, it was to find that the camp had been invaded by several enemies." "Could you not see whether they were Indians or otherwise?" asked the commander, as though a sudden suspicion had flashed through his brain. "It was very dark, and our eyes were not of much use, sir," the messenger told him in reply. "We purposely refrained from building anything but a small cooking fire, and that was in a hole so its light might not betray us to any wandering Indians. But they were not red men who attacked us; of that I am assured." "Why are you so certain of that?" inquired Captain Lewis. "We were all struggling with the intruders, who had evidently thrown themselves upon us just as my horse gave the warning whinny," the messenger explained. "I am positive that my hands did not clutch the greased body of a redskin, when I tried to throw him. Clothes he certainly wore, such as all frontiersmen do. I could feel the deerskin tunic, with its fringed edges. Besides, I tore a handful of his beard out in my struggles."