"We call them pebbles. To beings who might consider us giants--and if there really are intelligent beings in other worlds they might well be of an entirely different size from us, though no less dangerous for all that--they might seem huge meteors. Suppose that, though most of them would undoubtedly burn up and all of them be considerably reduced before they struck another planet as meteorites, some of them at least might still be sufficiently large to be analyzed chemically? And suppose that where they struck there existed beings capable of analyzing them?" * * * * * This was getting a little deep for anybody not a Thinker to take in. Several Council members raised their hands plaintively and so indicated. "All right, I'll try to make it plainer," Myrwan said. "Let us pretend that instead of the little fragments of space debris that fall harmlessly in the annual meteor showers here, we were pelted with enormous chunks of matter, perhaps causing major damage to property and life. Wouldn't We immediately undertake an intensive study to determine whence they came, and of what, precisely, they consisted? "And if We found that these residual meteorites contained material indicating their origin in an inhabited world--still worse, in a world sufficiently evolved to entail the possibility or probability that its highest life-forms might be intelligent or even civilized--wouldn't we take steps at once to investigate? Moreover, wouldn't we be outraged to the point where our primary object would be to avenge ourselves? "Of course we would. And so of course would any beings on other planets, under similar circumstances." "You mean," Marnag asked, "that if beings came here from space they would attack us?" "That too. But even if that were not their reaction, curiosity alone could be enough to spur them on to exploration." "But--but what can we do?" quavered old Gantes. He is really growing too senile to be on the Council much longer. "We can discourage them. And we can mislead them." "How?" "We can make certain that nothing reaches them in the future which gives them the least sign that any but the lowest forms of life, if even those, exist in our world. "I studied this whole question systematically, as We always do. I came to the conclusion that only the phph pebbles could possibly betray us. I attended a phph game to see for myself if a pebble actually could be thrown with sufficient force to become, as it were, an artificial meteor. I found that it could. Indeed, I saw Gral make such a throw." Gral looked stricken. He fell flat on his face, groveling before the Thinkers. "Oh, Your Reverences," he cried, "I never dreamt--I never--" "Get up, Gral," Myrwan ordered. "Nobody's blaming you. Nobody expects anyone but a Thinker to Think." "We'll make it a rule from now on to hold our shots. We'll bar anyone from the game forever who lobs a pebble too hard," Hodnuth promised fervently.