Lafond's knowledge of the topography of the place was excellent. He had visited it several times. He had watched the doctor, step by step, throughout a long day of geological searching. He knew Jim Buckley's dwelling, where he worked, what hours he kept, and just how late he sat up at night. Innumerable times he had viewed the doctor, Prue, and the scout through the buck-horn sights of his long rifle; yet he had never been even tempted to pull the trigger. Why? Because he was a Latin, and so theatrical effects were dear to him; because he was an Indian, and so revenge with him seemed to lie not so much in the mere infliction of injury as in the victim's realization that he was being come up with. Lafond not only wanted the doctor and his companions to be killed, but he wanted them to know why they were killed, and by whom. It was finer to be able thus to do the thing with all the stage settings. The dramatic instinct was part of the barbaric quality of his nature, like a love for red. So Lafond had let slip innumerable opportunities of picking off his victims single-handed, merely to gain the local knowledge necessary to a final _coup de théâtre_. Consequently, he knew where the cabin was situated, and quickly scouted the state of affairs. The coast was clear. He gave the required signal; the savages silently approached on foot, and they entered the little house together. Now at this time of year, in the Black Hills, there occurs a daily meteorological phenomenon of a rather peculiar character. The hot air from the prairies sweeps over from the Missouri River, crossing a number of lesser streams in its passage, until it strikes the slope of the hills. There it is deflected upward, gradually becoming colder as the elevation rises, until, at the barrier of Harney, it gathers in rain clouds. These are at first mere wisps of down, streaming in ragged ribbons from the peak; but with incredible rapidity they gain in density and extent, until they spread over a considerable area of the surrounding country. Then they empty themselves in a terrific deluge of water and hail, accompanied by thunderclaps so reverberant that they seem to arise from the rending of the hills themselves. After this short crisis, the dismembered clouds float out over the prairie and are dissipated in the hot air, even before they reach the first white turrets of the Bad Lands. So rapidly does the storm gather and break, that there is but a short half hour between the morning and the afternoon clearness of the skies. To those who have never experienced this phenomenon, it is startling in the extreme; to those who have, it is a matter of seeking temporary shelter until the disturbance blows over. In any case, the first indications are but scant warning.