It was a cold winter's evening late in the Stone Age; the sun had gone down blazing over the plains of Thold; there were no clouds, only the chill blue sky and the imminence of stars; and the surface of the sleeping Earth began to harden against the cold of the night. Presently from their lairs arose, and shook themselves and went stealthily forth, those of Earth's children to whom it is the law to prowl abroad as soon as the dusk has fallen. And they went pattering softly over the plain, and their eyes shone in the dark, and crossed and recrossed one another in their courses. Suddenly there became manifest in the midst of the plain that fearful portent of the presence of Man—a little flickering fire. And the children of Earth who prowl abroad by night looked sideways at it and snarled and edged away.