"Far from it," said Myrwan. "On the contrary, in the future you must concentrate on supra-gravity shots. Give extra points to anyone who performs one." "Why?" several of us murmured, completely bewildered. "Because I have already analyzed three pebbles I brought back with me from the game. With the ones you have brought, I shall be able to make further tests. If they confirm my previous findings, I Think We shall be able to mislead any potential attackers. "Every phph pebble henceforth will be doctored. To use any unauthorized pebble will become a felony. What has happened in the past we can't change, but there may still be time to save ourselves. From this time forth there are going to be more 'meteors' shot off our atmosphere than ever before--and every one of them is going to tell a completely false story about conditions in their place of origin. "Of course We _may_ be entirely wrong. These new waves may be due to purely physical causes. Other planets may all be as devoid of intelligent life as We have always assumed. But if there is the faintest possibility--and I feel there is--that we are in danger, it would be fatal not to take such measures as we can to avert it." "What's in the pebbles now that could tell anything about us?" Gral asked. "And if something is, how could you alter it?" * * * * * Myrwan froze up a little. The Thinkers don't like to have us ask detailed questions. But he realized that Gral was still upset, and answered kindly. "It wouldn't mean a lot to you if I told you. But you can understand this much--chemical analysis of the pebbles I've looked at so far shows fragments of embedded fossils." "Of plants, you mean?" Myrwan smiled. "Plants don't become fossilized," he said. "In one pebble there was a microscopic piece of a metal knife. In another there was half of a fossilized tooth. Ground Dweller relics, true, but human. You must remember that all the hills around here from which you gather the pebbles are really million-ganath-old burial places of the Ground Dwellers. We haven't bothered to dig up most of them because we're so rich in prehistoric remains, with our immensely old civilization, that we have all the fossils and ancient artifacts we need. "But let's imagine an alien civilization a great deal younger than ours. Let's imagine that in even one of those pebbles--which would be meteorites to them--even a minute trace of that kind of thing should be left. What would they Think?--for they would have to have Thinkers too, to be civilized at all. "I'll tell you what they'd Think. They'd decide that somewhere out in space there is a rich, undiscovered planet full of valuable knowledge and, even better, valuable artifacts. Probably a world with a culture much more advanced than their own. And they'd try hard to trace the direction from which those meteorites came, and to calculate the distance. Then suppose they had some means of transportation in space.