This remark will show whether or not the robber intended to abide by the promises he had just made to Arthur Vane; and, while we are on this subject, it may not be amiss to say, that the scheme Arthur had proposed, was one on which the robber had been meditating for many days. During the time he had lived in the mountains, he had kept his brain busy, and had been allowed ample opportunity to decide upon his future operations. He had been astonished and enraged at his failure to secure the twelve thousand dollars, and to make Frank Nelson a prisoner, and he had resolved to make amends for his defeat by capturing Frank and all his companions, including Arthur Vane. Pierre had plenty of friends to assist him, but there was one question that troubled him, and presented an obstacle that he could see no way to overcome; and that was, how to capture all the boys at once. That must be done, or his plan would fail. He could get his hands upon Arthur Vane at any time; but the others were like birds on the wing--here to-day, and miles away to-morrow--and Pierre did not know where to find them. Now, however, the difficulty was removed. Frank and his friends were going on a hunting expedition, Arthur would ascertain when they were going to start, and what road they intended to take, and when the day arrived, the robber could call in his men, who were employed on the neighboring ranchos, and capture the boys without the least trouble. Pierre was very glad that Arthur had got angry at Frank. Meanwhile Frank, Archie, and Johnny, all unconscious of the plans that were being formed against them, enjoyed themselves to the utmost, and wasted a good deal of time every day in laughing over the incidents that had transpired during their ride to Captain Porter's ranch. Archie, especially, had a great deal to say about it. He had an accomplishment, of which we have never before had occasion to speak: he was a first-class mimic; and he took no little pride in showing off his powers. He could imitate the brogue of an Irishman the broken English of a Dutchman, or the nasal twang of a Yankee, to perfection; and one day, while he was in the barn saddling his horse, he carried on a lengthy conversation with Bob Kelly (who was on the outside of the building), about some runaway cattle, and the old trapper thought all the while that he was talking to his chum, Dick Lewis. Now Archie had a new subject to practice upon. He laid himself out to personate Arthur Vane; and he not only successfully imitated that young gentleman's pompous style of talking, and his dignified manner of riding and walking, but even the tone of his voice. He criticised Frank and Johnny continually, and made them laugh, till their jaws ached, by recounting imaginary adventures on the burning sands of Patagonia, and among the icebergs and polar bears of India.