He explained. He was going to put a cloud of metallic vapor up in the ionosphere. Sodium if he had to, potassium if he could, zinc if he must. Those metals were readily ionized by sunlight, much more readily than atmospheric gases. In effect, he was going to supply a certain area of the ionosphere with material to increase the efficiency of sunshine in providing electric power. As a side-line, there would be increased conductivity from the normal ionosphere. "Something like this was done centuries ago, back on Earth," he explained. "They used rockets, and made sodium-vapor clouds as much as twenty and thirty miles long. Even nowadays the Survey uses test rockets with trails of sodium vapor. It will work to some degree. We'll find out how much." He felt Herndon's eyes upon him. They were almost dazedly respectful. But one of the technicians said: "How long will those clouds last?" "That high, three or four days," Bordman told him. "They won't help much at night, but they should step up power-intake while the sun shines on them." A man in the back said, "Hup!" The significance was, "Let's go!" Somebody else said feverishly, "What do we do? Got working drawings? Who makes the bombs? Who does what? Let's get at this!" Then there was confusion, and Herndon vanished. Bordman suspected he'd gone to have Riki put this theory into dot-and-dash code for beam-transmission back to Lani II. But there was no time to stop him. These men wanted precise information and it was half an hour before the last of them had gone out with free-hand sketches, and had come back for further explanation of a doubtful point, and other men had come in to demand a share in the job. When he was alone again, Bordman thought, _Maybe it's worth doing because it'll get Riki on the Survey ship. But they think it means saving the people back home!_ Which it didn't. Taking energy out of sunlight is taking energy out of sunlight, no matter how you do it. Take it out as electric power, and there's less heat left. Warm one place with electric power, and everywhere else is a little colder. There's an equation. On this colony-world it wouldn't matter, but on the home world it would. The more there was trickery to gather heat, the more heat would be needed.... Again it might postpone the death of twenty million people, but it would never, never prevent it.... The door slid aside and Riki came in. She stammered a little. "I just coded what Ken told me to send back home. It will--it will do everything! It's wonderful! I wanted to tell you!" "Consider," Bordman said, in a desperate attempt to take it lightly, "that I've taken a bow." He tried to smile. It was not a success. And Riki suddenly drew a deep breath and looked at him in a new fashion. "Ken's right," she said softly. "He says you can't get conceited. You're not satisfied with yourself even now, are you?" She smiled. "But what I like is that you aren't really smart. A woman can make you do things. I have!"