To the outermost planet of the System of Sirius the great machine fled. For years it remained there waiting, thinking. Then at last it called its worker machines into action. A new machine grew up from the stores of metal that the space ship had brought with it, at last the metal was used up, and the machine was not completed, so the space-flyer was sacrificed for the completion of the machine. The new machine was started. From its lip-like spout there poured a steady smooth stream of molten metal, and the rock on which it rested was eaten away. The first transmuting metal producer was made. Decades passed, and only a small percentage of man developed. The rest sank deeper and deeper into a life of ease. The planets were all explored by the hardy ones, and no trace of the brain-machine was ever found, for it had discovered the Dis ray, and sunk deep into the ground, hollowing a great cave to live and work in. * * * * * But back on that planet, the scientists had developed machines that surpassed it in power, and finally one of these picked up a thought message from that distant machine that told its story. It was a thought that had not been consciously radiated, only the marvelous sensitivity of this new machine could have detected it, but now the men knew. It was too late to do much to prevent it, for they had no weapons. But the machine did. It was preparing to drive man from the planets, to rule there in his stead, with a population of machines! The scientists quickly built a great space-flyer, a gigantic machine of over ten miles diameter, a huge sphere. And in that they established laboratories, workshops, machines, and living quarters. They took with them the finest men and women of their race, and sailed out into space, taking an orbit about the sun of Sirius. They were comfortable there in an equitable temperature, their ship lighted by the sun on one side, and dark on the other, steadily revolving on its axis like a miniature world. The foods of the people were chemically prepared, for the brain-machines had taught them how. The air was repurified constantly by machines that regulated the percentage of the gases to the thousandth of one per cent. But the entire ship was painted black. It could not be discovered floating there in space, so tiny in the vastness of a system! It was two weeks after they sailed that the machine-brain attacked. It sailed out of its hiding place with thousands of great ships, armed with Dis rays and with explosives, with heat rays and attractor beams. The population of those worlds was wiped out in a week, and the rule of the Metal Horde began. The original brain built other brain-machines to direct its affairs on other planets, and to do the work it did not wish to do itself.