They were flying past at a tremendous speed, so that the watcher had to strain hard to catch details; when all at once he beheld just above the line of the topmost peaks a dark and moving object against the stars, whose course exactly paralleled that of his own bizarre party. The ghouls had likewise glimpsed it, for he heard their low glibbering all about him, and for a moment he fancied the object was a gigantic Shantak, of a size vastly greater than that of the average specimen. Soon, however, he saw that this theory would not hold; for the shape of the thing above the mountains was not that of any hippocephalic bird. Its outline against the stars, necessarily vague as it was, resembled rather some huge mitred head, or pair of heads infinitely magnified; and its rapid bobbing flight through the sky seemed most peculiarly a wingless one. Carter could not tell which side of the mountains it was on, but soon perceived that it had parts below the parts he had first seen, since it blotted out all the stars in places where the ridge was deeply cleft.