He could not help scanning the sky for the expected robot bombers. The preoccupation caused him to stumble and fall to his knees as he reached the crest. He skinned them further crawling the last two meters to the shade under the nearest of the dwarf trees. According to his theory it wouldn’t matter much whether or not he concealed himself. Still, Robert sought heavy cover. The Gubru machines might have simple optical scanners to supplement their primary homing mechanism.

He heard shouting below, sounds of chims in fierce argument. Then, from somewhere to the north, there came a faint, whining sound.

Robert backed further into the bushes, though sharp twigs scratched his tender skin. His heart beat faster and his mouth was dry. If he was wrong, or if the chims decided to ignore his command…

If he had missed a single bet he would soon be on his way to internment at Port Helenia,’ or dead. In any event, he would have left Athaclena all alone, the sole patron remaining in the mountains, and spent the remaining minutes or years of his life cursing himself for a bloody fool.

Maybe Mother was right about me. Maybe I am nothing but a useless playboy. We’ll soon see.

There was a rattling sound — rocks sliding down the boulder scree. Five brown shapes tumbled into the foliage just as the approaching whine reached its crescendo. Dust rose from the dry soil as the chims turned quickly and stared, wide-eyed. An alien machine had come to the little valley.

From his hiding place Robert cleared his throat. The chims, obviously uncomfortable without their clothes, started in tense surprise. “You guys had better have thrown everything away, including your mikes, or I’m getting out of here now and leaving you behind.”

Benjamin snorted. “We’re stripped.” He nodded down into the valley. “Harry an’ Frank wouldn’t do it. I told ’em to climb the other slope and stay away from us.”

Robert nodded. With his companions he watched the gasbot begin its run. The others had witnessed this phenomenon, but he had not been in much shape to observe during the one opportunity he’d had before. Robert looked on with more than a passing interest.

It measured about fifty meters in length, teardrop-shaped, with scanners spinning slowly at the pointed, trailing end. The gasbot cruised the valley from their right to their left, disturbed foliage rustling beneath its throbbing gravities.

It seemed to be sniffing as it zigzagged up the canyon — and vanished momentarily behind a curve in the bordering hills.

The whine faded, but not for long. Soon the sound returned, and the machine reappeared shortly after. This time a dark, noxious cloud trailed behind, turbulent in its wake. The gasbot passed back down the narrow vale and laid its thickest layer of oily vapor where the chims had left their clothes and equipment.

“Coulda sworn those mini-corns couldn’t have been detected,” one of the naked chims muttered.

“We’ll have to go completely without electronics on the outside,” another added unhappily, watching as the device passed out of sight again. The valley bottom was already obscured.

Benjamin looked at Robert. They both knew it wasn’t over yet.

The high-pitched moan returned as the Gubru mechanism cruised back their way, this time at a higher altitude. Its scanners worked the hills on both sides.

The,machine stopped opposite them. The chims froze, as if staring into the eyes of a rather large tiger. The tableau held for a moment. Then the bomber began moving at right angles to its former path.

Away from them.

In moments the opposite hill was swathed in a cloud of black fog. From the other side they could hear coughing and loud imprecations as the chims who had climbed that way cursed this Gubru notion of better living through chemistry.

The robot began to spiral out and higher. Clearly the search pattern would soon bring it above the Earthlings on this side.

“Anybody got anything they didn’t declare at customs?” Robert asked, dryly.

Benjamin turned to one of the other neo-chimps. Snapping his fingers, he held out his hand. The younger chim glowered and opened his hand. Metal glittered.

Benjamin seized the little chain and medallion and stood up briefly to throw it. The links sparkled for just a moment, then disappeared into the murky haze downslope.

“That may not have been necessary,” Robert said. “We’ll have to experiment, lay out different objects at various sites and see which get bombed. …” He was talking as much for morale as for content. As much for his morale as for theirs. “I suspect it’s something simple, quite common, but imported to Garth, so its resonance will be a sure sign of Earthly presence.”

Benjamin and Robert shared a long look. No words were needed. Reason or rationalization. The next ten seconds would tell whether Robert was right or disastrously wrong.

It might be us it detects, Robert knew. Ifni. What if they can tune in on human DNA?

The robot cruised overhead. They covered their ears and blinked as the repulsor fields tickled their nerve endings. Robert felt a wave of déjà vu, as if this were something he and the others had done many times, through countless prior lives. Three of the chims buried their heads in their arms and whimpered.

Did the machine pause? Robert felt suddenly that it had, that it was about to …

Then it was past them, shaking the tops of trees ten meters away… twenty… forty. The search spiral widened and the gasbot’s whining engine sounds faded slowly with distance. The machine moved on, seeking other targets.

Robert met Benjamin’s eyes again and winked.

The chim snorted. Obviously he felt that Robert should not be smug over being right. That was, after all, only a patron’s job.

Style counted, too. And Benjamin clearly thought Robert might have chosen a more dignified way to make his point.

Robert would go home by a different route, avoiding any contact with the still-fresh coercion chemicals. The chims tarried long enough to gather their things and shake out the sooty black powder. They bundled up their gear but did not put the clothes back on.

It wasn’t only dislike of the alien stink. For the first time the items themselves were suspect. Tools and clothing, the very symbols of sentience, had become betrayers, things not to be trusted.

They walked home naked.

It took a while, afterward, for life to return to the little valley. The nervous creatures of Garth had never been harmed by the new, noxious fog that had lately come at intervals from a growling sky. But they did not like it any more than they liked the noisy two-legged beings.

Nervously, timorously, the native animals crept back to their feeding or hunting grounds.

Such caution was especially strong in the survivors of the Bururalli terror. Near the northern end of the valley the creatures stopped their return migration and listened, sniffing the air suspiciously.

Many backed out then. Something else had entered the area. Until it left, there would be no going home.

A dark form moved down the rocky slope, picking its way among the boulders where the sooty residue lay thickest. As twilight gathered it clambered boldly about the rocks, making no move to conceal itself, for nothing here could harm it. It paused briefly, casting about as if looking for something.

A small glint shone in the late afternoon sunshine. The creature shuffled over to the glittering thing, a small chain and pendant half hidden in the dusty rocks, and picked it up.

It sat looking at the lost keepsake for a time, sighing softly in contemplation. Then it dropped the shiny bauble where it had lain and moved on.

Only after it had shambled away at last did the creatures of the forest finish their homeward odyssey, scurrying for secret niches and hiding places. In minutes the disturbances were forgotten, dross from a used-up day.