He prodded about among the weapons, shaking his head. "All the weapons in places like this show evidence of one homogeneous design. And all the ornaments are in a T shape, like this one." He lifted a stainless metal object from the floor and dropped it. "But outside in the square, there are at least two designs. For once, it almost looks as if your idea of an alien invader might be worth considering." The radio at his side let out a squawk, and he cut it on listening to the thin whisper that came from it. Abruptly, he swung about and headed toward his tractor outside, with Lenk following. "Aimes has found something," Jeremy said. They found the linguodynamicist in the gutted ruins of a building into which great concrete troughs led. A rusty ruin in one of the troughs indicated something like a locomotive had once run in it, apparently on great ball bearings. The fat man was pointing excitedly toward something on one of the walls. At first glance, it seemed to be a picture of more of the green people, apparently undergoing some violent torture. Then their eyes swept on--and they gasped. Over the green people, three vaguely reptilian monstrosities were hovering, at least twice the size of the others, all equipped with the fanged whips Lenk had seen. One of the green men was apparently trying to defend himself with a huge T-shaped weapon, but the others were helpless. The reptilian monsters sprouted great ugly wings of glaring red from their shoulders. "The invaders," Lenk said. They were horrible things to see. "But their weapons weren't that big...." "A war poster!" Aimes said bitterly. "It doesn't tell a thing except that there were two groups." Jeremy studied it, more closely. "Not necessarily even that. It's designed for some emotional effect. But at least, it's a hint that there may have been enemies unlike the ones who lived here. Lenk, can I take the scout ship out?" "Go ahead," Lenk told him. He frowned at the poster. "Jeremy, if that means the human race is going to have to face an alien invasion from monsters like that...." "It means nothing!" Jeremy went off, with Aimes apparently in agreement for a change. Lenk stood studying the poster. Finally he ripped it down, surprised to find how strong it still was, and rolled it up to carry back to the ship. Each world had been razed more recently, and each with the same curious curse. The race had risen to a high culture, and then had seemingly been wiped out in a few brief years. The destruction had accounted for all life on the planet, other than vegetable--and had wiped out even the bones. All that had been left was a collection of weapons and relics of more doubtful use. The pattern was the same. The direction was steadily toward Earth, leaping from planet to planet at jumps of thousands of years apart, or perhaps mere hundreds. This planet must have been attacked less than five hundred years before, though it was hard to tell without controlled study of decay here.