"It's the same among my people," Dworn said hushedly. "There's no record of the drones' having appeared in the time of anyone now living.... But here they are."

From out of sight came the rattle and clank and whine of machines at work. And from farther away, from the direction of the great windowless buildings, there were hootings and throbbing sounds, and from time to time a deep rumbling that shook the earth.

Those noises were somehow unspeakably horrible now--now that they knew there was no one there. No one--nothing but the machines, without feeling or thought, without life, with only the blind meaningless activity of unliving mechanism set in motion and made self-subsisting a thousand or two thousand years ago....

With infinite caution the two humans peeked once again over the summit of the mound. Out there on the flat, the little wingless drones buzzed to and fro with their false seeming of animation, finishing their work.

From around the great buildings, whose interior no living eyes had ever looked upon, lights winked oddly blue through the thickening dusk. They caught glimpses of immense moving machinery, and heard mysterious sounds. Once and again, it seemed that in the open s.p.a.ce before the structures a great door opened in the earth, and against a blue light that streamed upward they saw a vast winged shape rise majestically from underground and roll slowly forward into the shadows to join others already ranked there.

"What are they doing?"

"I don't know...." Dworn reflected, grasping at memories of the legends, the traditions he had heard. What he recalled was ominous. "I think I can guess, though. I think they're getting ready to swarm."

Her stifled exclamation was sign enough that she understood.

If the guess was right, the danger was on the verge of being multiplied many times over. Soon now, a swarm of queen ships would take to the air and fly in all directions, sowing the seed of the robot plague broadcast far and wide; one such colonizing vessel, no doubt, had founded this great hive only a few months ago. The things worked fast....

And Dworn's duty, and Qanya's, became all the more clear and urgent.

Duty to spread the warning, at whatever risk to themselves. In the face of that, Dworn's mission of personal blood vengeance became unimportant--even if it had been possible to take such vengeance upon a foe with no life to forfeit.

He whispered to Qanya, "The ground machines are about to leave. When they're gone, we'll have to make a break for it." For some reason, as he pondered the distance they must cross to reach the Barrier cliffs, he recalled the strange revolving thing atop the central tower off yonder, turning constantly with its air of restless searching.... He swallowed painfully, repeated, "_Have_ to."

The girl nodded silently. Impulsively Dworn put his arm around her; she pressed close against him. They huddled together like that, finding in one another's living warmth some measure of encouragement against the terror of the falling night in which nothing moved but the lifeless machines.

They watched while the lights glimmered far off across the flats; while a flight of fighter drones took off from there and howled away into the dark on some roving patrol; while, at last, the salvaging machines finished their work and rolled loot-laden away one by one.

More than once while they waited, other columns of the wingless drones entered or emerged from the tunnel mouth at the base of the mound. The tempo of activity in the hive was, if anything, increased as night came on. In the deepening darkness a faint blue glow streamed from the tunnel mouth.

As the whirring of the last salvager receded, Dworn got cautiously to his feet. He said between his teeth, "We'd better move fast, now--"

"Wait," said Qanya tensely. "They'll sight us in the open, and then what chance will we have?"

Dworn tried to make out her expression, but in the darkness her face was only a white blur. "We've got to try. There's no other way."

"Perhaps there is. What about the tunnel?"

Dworn was brought up short; that idea hadn't occurred to him at all. He said slowly, "I see what you mean, It's only big enough for one-way traffic--and the drones evidently have some system of remote control, so that outbound expeditions aren't using it at the same time as returning ones...."

"So, if we wait till some of the wingless ones enter from this end, and hurry through the tunnel close behind them--" Qanya left the sentence uncompleted. Dworn knew she could imagine as well as he what would happen if they failed to time it right, and met a drone column coming from the opposite direction. Still, the sound sense of the girl's ideas was obvious.

"All right," he said. "We'll try it that way."

It was another nerve-fraying wait until a file of ground machines came winding near and vanished one after another into the tunnel.

The two watchers gave them a little time--not too much--to get clear of the entrance. Then Dworn clasped Qanya's hand tightly in his own, and together they plunged down the sliding slope of the sandhill. The tunnel mouth yawned in its side, the bore on which it opened slanting steeply down into the earth, inwardly lit with eery blue light.

Hearts pounding, they raced into the tunnel.

It was an unreal, nightmare flight. The blue shaft curved and descended endlessly. Endlessly ahead of them echoed the snarling of drone engines.

They ran with lungs near to bursting, through air heavy and foul with exhaust gases--trying frantically to keep close behind that engine noise, while it receded inexorably before them. And once and again, amid the tricky tunnel echoes, Dworn was almost sure that other drones had entered and were descending the narrow way behind them, and before his eyes flashed hideous visions of the two of them overtaken and run down, here where there was scarcely room to turn, let alone fight or hide.

The featureless walls were pressing inward to crush them, swimming before eyes filmed with exhaustion, in the blue shimmer which no doubt sufficed for the perceptions of the drones but which hardly served human vision....

The tunnel was in fact perhaps a thousand yards long.

But it seemed as if they had been staggering for a lifetime through the nightmare, through the blue glow, and it scarcely seemed real when a patch of night sky showed through the exit before them, and when they stumbled panting out into the clean cold air of the mountainside, and saw the white radiance of moonrise over the Barrier cliffs above them.

They sank down to catch their breath on a rock not far from the tunnel.

They'd made it none too soon--only a minute or two had pa.s.sed when the night once more buzzed with motor noise, and a column of foraging drones rolled up the trail and plunged at full speed into the mouth of the shaft.

Qanya buried her face against Dworn's shoulder.

"Easy, now," Dworn whispered, patting her with clumsy gentleness. "The worst's over. We made it ... Qanya, darling, we made it!"

She looked up at him and by the moonlight he saw her smile tremulously.

She said breathlessly, "Would ... would you mind saying that again, please?"

The moon was already high as they trudged across the rolling desert beyond the foot of the great landslip.

After the tunnel, the rest of the descent had been relatively easy; they had followed the trail used by the wingless drones, being forced off it only once by the pa.s.sage of a cavalcade of the little marauders. And they had discovered, to their surprise, that the human physique--inferior though it might be to machines in ruggedness, speed, and other respects--was better equipped for traversing rough terrain than the most ingenious vehicle ever constructed.

But both of them, unaccustomed as they were to walking on their own feet, were dead weary. They tramped on doggedly, searching the shadows, hoping to come upon some living machine-creature--of what race, didn't matter now.

So far they had seen only abundant evidence that the drones were abroad in force tonight, preparing perhaps for their swarming time. Drones in the air and on the ground, and once the burnt-out sh.e.l.l of an unidentifiable machine with a crew of the wingless salvagers worrying it, and once the light of fires afar off where the winged ones had made a kill....

Qanya stumbled, and Dworn caught her round the waist as she swayed.

"Tired," she gasped in a little girl's voice, then stiffened her back with a resolute effort.

"We'd better rest--"

"No," she said shakily; and then abruptly: "_Listen!_"

Not very far away, lost somewhere among the tricky moon-shadows, there was a stealthy crunching. It was coming nearer.

With instinctive caution the two hugged the pool of shadow beside a boulder.

"Spiders!" Qanya recognized them first.

They came prowling out of the shadows, crunching rhythmically across an open moonlit s.p.a.ce towards a hollow beyond. One, two, four of them, moving with furtive caution through the perilous night.

They had to be intercepted, the warning given. But it was a critically dangerous moment--suspicious and on edge, they might fire at the first movement they saw.

"Stay here," said Dworn shortly. He thrust Qanya back into the shadows, and walked steadfastly out into the clear moonlight, in the path of the walking spider machines.