Tom Brown had lead the last revolt against the Martian government, an ill-starred revolt that ended almost before it started when the troopers turned loose the heavy heaters and swept the streets with washing waves of flame. When he climbed to the base of a statue in Techor Park to address the crowd that gathered, the police shouted for him to come down and he disregarded them. They climbed the statue to reach him and their hands went through him. Tom Brown stood before the people, in plain view, and spoke, but he wasn't there! Other things happened in Sandebar that day. A voice spoke out of thin air, a voice that told the people the reign of Interplanetary was over. It told of a mighty new source of power. Power that would cost almost nothing. Power that would make the accumulators unnecessary ... would make them out of date. A voice that said the people need no longer submit to the yoke of Spencer Chambers' government in order to obtain the power they needed. There was no one there ... no one visible at all. And yet that voice went on and on. A great crowd gathered, listening, cheering. The police tried to break it up and failed. The troops were ordered out and the people fought them until the voice told them to disband peaceably and go to their homes. Throughout Mars it was the same. In a dozen places in Sandebar the voice spoke. It spoke in a dozen places, out of empty air, in Malacon and Alexon and Adebron. Tom Brown, vanishing into the air after his speech was done, reappeared a few minutes later in Adebron and there the police, warned of what had happened in Sandebar, opened fire upon him when he stood on a park bench to address the people. But the flames passed through and did not touch him. Tom Brown, his long white beard covering his chest, his mad eyes flashing, stood in the fiery blast that bellowed from the muzzles of the flame rifles and calmly talked. * * * * * The chief of police at New Chicago, Venus, called the police commissioner. "There's a guy out here in the park, just across the street. He's preaching treason. He's telling the people to overthrow the government." In the ground glass the police commissioner's face grew purple. "Arrest him," he ordered the chief. "Clap him in the jug. Do you have to call me up every time one of those fiery-eyed boys climbs a soap box? Run him in." "I can't," said the chief. The police commissioner seemed ready to explode. "You can't? Why the hell not?" "Well, you know that hill in the center of the park? Memorial Hill?" "What has a hill got to do with it?" the commissioner roared. "He's sitting on top of that hill. He's a thousand feet tall. His head is way up in the sky and his voice is like thunder. How can you arrest anybody like that?" * * * * *