That afternoon, Dan and the Milbuns passed three average-looking men hanging by their hands from the limb of a tree beside the trail. The faces of the hanging men bore a surprised expression. They hung perfectly still and motionless, except for a slight swaying caused by the wind. Dan and the Milbuns reached a mataform station late that afternoon. A very hard-eyed guard in an orange cape, barred across the shoulders in black, let them through and they found themselves in another spaceship, bound for Fumidor, the mining planet. * * * * * Dan sat back exhausted and fell asleep. He was awakened by a determined buzz. "_Dan!_" said Kielgaard's voice. "Yes." Dan sat up. "Go ahead." "Trans-Space is going to try to take over Porcys. There's nothing you can do about that, but they've landed agents on Vacation Planet to pick you off. Look out." Dan told Kielgaard what had happened to the agents on Vacation Planet, such as the "undevised" explosion and being hung up by the hands. Kielgaard whistled. "Maybe the Porcyns can take care of themselves. Trans-Space doesn't think so." "How did you find out?" The tiny voice held a note of grim satisfaction. "They ran an agent in on us and he gave himself away. He went back with an organo-transmitter inside him, and a memory bank. The bank stores up the day's impressions. The transmitter squirts them out in one multi-frequency blast. The agent is poorly placed for an informant, but we've learned a lot through him." "How are they going to take over Porcys?" "We don't know. They think they've found the Porcyns' weak point, but if so, we don't know what it is." "Listen," urged Dan, "maybe _we_ ought to put a lot of agents on Porcys." "No," said Kielgaard. "That's the wrong way to play it. If we go in now, we'll be too late to do any good. We're still counting on you." "There's not very much I can do by myself." "Just do your best. That's all we can ask." Dan spent the next week chipping out pieces of a radioactive ore. At night, Kielgaard would report the jubilant mood of Trans-Space. On the following days, Dan would chop at the ore with vicious blows that jarred him from his wrists to his heels. The steady monotonous work, once he was used to it, left his mind free to think and he tried furiously to plan what he would do when he got out. But he found he didn't really know enough about Porcys to make a sensible plan. Then he began trying to organize what he had seen and heard during his stay on the planet. At night, Kielgaard helped him and together they went over their theories, trying to find those that would fit the facts of Porcys. "It all hinges on population pressure," said Kielgaard finally. "On most planets we know of, overpopulation leads to war, starvation, birth control or emigration. These are the only ways. At least, they were, till we discovered Porcys." * * * * *