At last the invaders were seen. Far out in their course the scouts had met them. Those scouts were destroyed, without provocation; they did not even have time to finish their reports, but we learned enough. Mars was a deserted planet now. All its population had moved to the other worlds. Most of them moved to Earth, on the other side of the sun. Only the workers in the great factories remained. They were not compelled to. They were told of the danger of their position, but those factories could contribute 1500 ships an hour, and they were manned. The fleet had gathered on Mars, awaiting the news of the Sirians, when the report of the scouts was flashed across the ether. They told of a great horde of metal ships, shining, iridescent, ranging in size from tiny darting machines, ten feet long by one and three-quarters in diameter, mere torpedoes, to great transport ships. And there was a single spherical ship. A great sphere that floated in the center of a bodyguard of the thousands of its followers. There were literally hundreds of thousands of the little torpedo-ships, a few dozen of the cargo ships, and a few ships that seemed more like scouts of some sort. But it was apparent that the little torpedo-ships were the real fighters--tiny ships that spun and turned and darted like an electron in ionized gas. It seemed impossible that a man could stand those sudden turns at several miles a second, but they watched them, and went into nothingness as the Dis ray reached out from those tiny ships and caressed their ships. They, too, had Dis rays--it would be a terrible battle, for man had that same force, a force so deadly they had feared to use it in industry. But man had the advantage of numbers. The men on the fleet who saw those television plates glowing with the story of what was taking place out there in space decided that those torpedo-ships must be guided by radio. If they were it would be a simple matter to wreck that system by using a powerful interference that would drown out the directing wave and make its ships unmanageable. The System Capital was temporarily moved to the Waterson Laboratories on Earth. There the forty men had gathered around great television plates and were watching the battle of the scouts. They were not to go to that battle front. The System needed them. * * * * *