"Our technical achievements may disappoint you," warned Crandon. "Oh, they're way beyond anything that you are familiar with. You've undoubtedly noticed the shielding material on the reactor. That's a fairly recent development of our metallurgical department. There are other things in the laboratory that I can't even explain to you until you have caught up on the technical basis for understanding them. "Our emphasis has not been on physical sciences, however, except as they contribute to our central project. We want to change civilization so that it can use physical science without disaster." For a moment Don had been fired with enthusiasm. But at these words his heart sank. "Then you've failed," he said bitterly. "In spite of centuries of advance warning, you've failed to change the rest of us enough to prevent us from trying to blow ourselves off the Earth. Here we are, still snarling and snapping at our neighbors' throats--and we've caught up with you. We have the atomic bomb. What's POSAT been doing all that time? Or have you found that human nature really can't be changed?" "Come with me," said Crandon. He led the way along the narrow balcony to another door, then down a steep flight of stairs. He opened a door at the bottom, and Don saw what must have been the world's largest computing machine. "This is our answer," said Crandon. "Oh, rather, it's the tool by which we find our answer. For two centuries we have been working on the newest of the sciences--that of human motivation. Soon we will be ready to put some of our new knowledge to work. But you are right in one respect, we are working now against time. We must hurry if we are to save our civilization. That's why you are here. We have work for you to do. Will you join us, Don?" "But why the hocus-pocus?" asked Don. "Why do you hide behind such a weird front as POSAT? Why do you advertise in magazines and invite just anyone to join? Why didn't you approach me directly, if you have work for me to do? And if you really have the answers to our problems, why haven't you gathered together all the scientists in the world to work on this project--before it's too late?" Crandon took a sighing breath. "How I wish that we could do just that! But you forget that one of the prime purposes of our organization is to maintain the secrecy of our discoveries until they can be safely disclosed. We must be absolutely certain that anyone who enters this building will have joined POSAT before he leaves. What if we approached the wrong scientist? Centuries of accomplishment might be wasted if they attempted either to reveal it or to exploit it!