"Boss of this outfit, I take it?" said the new arrival shortly. "Yes. Allow me to offer you my most grateful thanks for--" "Well, there's a big lot of Sioux preparing to `jump' you at any moment. Corral your waggons without delay, and have your cattle brought in at once. Not a second to lose." A frightful yell drowned his words. There was a thunder of hoofs upon the turf as a band of some fifty mounted Indians, dashing from their cover, bore down upon the herd of draught stock which was being driven back from the water in charge of three or four men. On came the savages, whooping and whistling, brandishing blankets and buffalo robes with the object of stampeding the now frantic cattle. But among those in charge of the latter there chanced to be a couple of experienced plainsmen. In a trice there rang out three shots, and two of the assailants' ponies went riderless. Crack--crack! Another pony went down. This was more than the redskins could stand. Like a bird of prey alarmed in its swoop, the entire band swerved at a tangent and skimmed away over the plain as fast as their ponies could carry them. The herd was saved. "There goes the first act in the drama," said the stranger coolly. "Now stand clear for the second." The suddenness of it all--the yelling, the shots, the swoop of the painted and feathered warriors--had created a terrible panic in the camp, and had the main body of the savages charged at that moment nothing could have saved its inmates. As the stranger had at first conjectured, two of the waggons were full of women and children, the families of some of the emigrants. These at once rushed to the conclusion that their last hour had come, and shrieks and wailings tended to render confusion worse confounded. But Major Winthrop, with military promptitude, had got the men well in hand, and a very few minutes sufficed to corral the waggons, bring in the cattle, and put the whole camp into a creditable state of defence. It was now nearly dark. "Will they attack us to-night?" enquired Major Winthrop, as, having completed his arrangements, he returned to where the stranger was seated smoking a pipe and gazing narrowly out into the gloomy waste. "I should be inclined to say not. Their surprise has fallen through, you see, and then Indians don't like fighting at night. But it's at the hour before dawn, when we're all infernally sleepy and more or less shivery with being up all night--it's then we shall have to keep a very bright look-out indeed. I should keep about half your men at a time on guard all night through if I were in your place." "Who air you, stranger?" said a not very friendly voice.