Dworn wrenched open the cabin door with one hand. His other arm circled Qanya's waist, dragged her away from the controls. She cried in uncomprehending shock as he swung her before him into the open doorway.

They swayed there, high above the speeding ground, wind whipping at them as the spider pounded blindly on.

The mound loomed immediately at hand. Dworn prayed that he had judged the moment right, and with a mighty leap launched both of them out into s.p.a.ce.

A pistoning steel leg barely missed them. Even as they fell, the air was torn by explosions as the swooping fliers opened fire.

Dworn hit the ground with almost stunning force. His hold on the girl was broken and he was rolled helplessly over and over by his own momentum. But he fetched up on hands and knees, bruised and breathless but unhurt.

From the corner of his eye he saw Qanya sitting up dizzily, half-buried in the drifted sand that had broken their fall. Apparently she too was uninjured, but she was staring in horrified fascination after her runaway machine.

The spider careened onward, no hand at its controls. It hit the line of crawling little machines coming from underground; it knocked one spinning end over end, and stepped squarely on another, stamping it flat. It recovered its balance amazingly, and loped on, even though one leg was buckling beneath it--

Then it was. .h.i.t dead-on by what must have been at least a hundred-pound high explosive rocket.

The winged killers shot low overhead with an exultant whoop of jets, peeling off to right and left of the column of smoke that rose and towered where the spider had been struck. Out of the cloud, metal fragments soared glinting upward and arced back to earth, and on the ground, amid smoke and dust, a metal limb was briefly visible, flexing convulsively and growing still.

Dworn heard a smothered sound beside him. A tear rolled down Qanya's smudged cheek, and Dworn thought fuzzily, _Even spiders can cry_.

_Only_, he corrected, _she's not a spider any more she's now just a ghost like me_.

If he hadn't been a ghost already, if he hadn't lost his own machine--the idea of jumping clear and saving both their human lives while letting the spider be destroyed would never have occurred to him.

He came to himself, hissed, "Down! Keep low and maybe they'll overlook us!"

They huddled together on the slope of the sandhill, while the victorious flying enemy circled round in a miles-wide sweep and began descending toward their base again, wing-flaps braking them for landing.

And on the ground meanwhile, the crawlers which had come from the tunnel were proceeding on their way, leaving two of their number behind with strange indifference to their own casualties.

"What'll we do?" quavered Qanya.

Dworn had time to take stock of the situation. The tunnel-mound was, as he had seen before, the only cover--and that a poor one--for a considerable distance. It was all of a quarter mile to the edge beyond which the cliffs fell away.

He tried to sound hopeful--whether for Qanya's sake or to keep up his own courage, he could hardly have said. "I think we'll have to stay here, and hope we're not noticed, until it gets dark. Then, maybe--"

Qanya caught her breath sharply and gripped his arm. "Look--there!"

Still far away across the sloping floor of the great bowl, but rapidly approaching from its center, moved a dust cloud. Beneath it, the expiring sunlight glinted on the aluminum sh.e.l.ls of at least a score of the ground machines.

Dworn said grimly, "Might have expected it; they'll be coming to look over the scene of action and pick up the pieces. We've one chance; keep out of sight behind this little hill, and maybe they won't investigate too closely."

Qanya nodded, biting her lip. She could reckon as well as he how much that chance was worth.

The buzzing motors came nearer. The two cowering in the lee of the mound, almost without daring to breathe, heard them halt, slow to idling speed one by one a little way off, where the wrecked spider lay. From that spot obscure sounds began rising, thuds and gratings and a shrill hissing noise.

But then--the whine of a single high-speed engine rose again, clear to their hearing. One of the enemy was approaching around the flank of the sandhill.

They crouched motionless, frozen. No hope in either flight or fight; on the open ground, they would be run down in no time, and they had no weapons--even the notion of a weapon, as something apart from the fighting machine that carried it, was alien to their thinking.

The enemy vehicle rolled into full view and nosed slowly along the base of the mound; its motor whining questingly, only a few yards of gentle slope between it and the huddled pair. Its vision-ports glinted redly in the sunset glow, and Dworn could almost feel the raking of murderous eyes from behind them.... Like the other machines of this kind he had seen it was small and without armor--it couldn't weigh more than a couple of thousand pounds, and it carried no guns. From the vantage of his armed and armored beetle, he had regarded its like as flimsy and harmless-looking.... But now he realized for the first time how helpless a mere human was against such a thing, and, with an irrepressible shudder, how easily the grappling and cutting-tools this one was equipped with might be employed for--dismantling--flesh and blood.

The machine paused momentarily. Then its engine revved up again. It rolled on past, giving no sign of excitement, and vanished beyond the hillside.

"Dworn, Dworn, it didn't see us!" Qanya was sobbing with relief.

Dworn was staring after the enemy, brows puzzledly drawn downward. The sounds from the other side of the mound went on uninterrupted--a clangor of metal, the prolonged shrilling of a cutting-torch, where evidently they were at work breaking up the smashed spider-vehicle.

He said huskily, "Something's very queer about them.... Wait. I've _got_ to take a look."

Qanya glanced at him in quick alarm as he started wriggling to the crest of the sandhill. Then she followed silently, and peered over the top beside him.

Twilight was descending, but they could still see easily enough what went on out there. Not a hundred yards away, the little machines swarmed about the spider, bringing their various wrecking equipment into play to dismantle it rapidly under the watchers' eyes. Torches flared, winches tugged at fragments of the shattered monster. An aluminum cylinder with a serrated alligator snout rolled triumphantly away, bearing aloft the shank of a great steel leg....

But Dworn's attention was riveted by what was happening closer at hand.

Here, near the tunnel-entrance that opened just below their observation point, lay the two crawlers which the runaway spider had disabled. One of these, the one which had merely been overturned and severely dented, was already being dragged away, wheels still helplessly in the air, by a towing-machine. The other had been smashed beyond repair. Around it several of the new arrivals were busy, callously and efficiently beginning to take it apart.

Dworn watched them at it, and the dreadful suspicion that had budded in his mind ripened into a monstrous certainty.

Aluminum skin was swiftly stripped away; frame members of the same metal were clipped neatly asunder by a machine armed with great shearing jaws.

The engine came loose and was hoisted aloft carried dangling away by another specialized machine. In an incredibly short time, little but a bare cha.s.sis remained, and that too was being attacked by the salvagers.

And Dworn knew at last beyond all doubt, what manner of things these were.

Beside him he heard a sharp gasp, and turned to put a warning finger on Qanya's lips. He drew her gently back with him, out of view of the activities on the farther side of the mound.

"You understand what _that_ means?"

The girl nodded soberly. "We have the tradition. I think that must be one tradition that all the peoples have in common."

"Then you know what we have to do."

She nodded again.

Between them the word hung unspoken--a word not to be uttered lightly, so awful was it in its connotations, freighted with memories of a terror rooted in the youth of the world.

_Drones._

In the beginning--said the stories--there were the ancients, who were great and powerful beyond the imagining of the latter-day peoples. But the ancients were divided among themselves, for some of them were good and some of them were evil.

So they fought one another, with the terrific weapons of devastation which they owned. And the good triumphed in the end, as it must--though at terrible cost, for in those wars the earth was stripped almost lifeless; searing flame, plague, climatic convulsions wiped out the varied life which once populated the world, and finally there remained only the peoples of the machine, all of whom--diverse though their ways of existence had become, and for all that they lived in ceaseless conflict with each other--were descended from the victors in that primal struggle of men like G.o.ds.

But the evil old ones, though they were vanquished and their seed utterly annihilated, had nevertheless found a way to perpetuate their evil upon the earth. For before the last of them died, as a final act of vindictive atrocity, they created the drones....

Qanya was shivering uncontrollably. She whispered, "No one remembers when they last came. Some thought there were none left in the world."