Chapter IV

Brownell told them later, in great excitement: "I swear to you, it defies all physical laws as we know them! It's merely a shiny chunk of rock, a few yards in diameter--but do you know, I believe it actually feeds upon gravity! I have always believed that gravity, magnetism, and other such universal forces are all a part of the electrical spectrum. Some peculiarity in the atomic structure of this Stone draws the straight-line force of gravity to it, and that force is then oscillated, transmitted into light! The process is unending!"

"That's all very well," Mark told him, "but I believe the greatest miracle is right here in the laboratories. These people have had to utilize the barest elements of this world, but they've done wonders. They have plastiglass, and farm implements, and electrical power--even crude atomic furnaces."

"They'd have their neutro-pistols right now," Janus agreed, "but they hit the same stumbling block that baffled our scientists for so long."

For days they worked ceaselessly on the neutro-pistols. Mark and the Professor together laid out the blueprints, devising a radical and more potent design for the firing coils. The latter was surprised at Mark's knowledge of electronic principles.

"I may surprise you even further, one of these days," Mark promised.

And now the urgency of their work was really impressed upon them. Scouts returning each day from the twilight zone reported that the Perlacs were gathering. Thousands of them swarmed the forests on the dark side, apparently massing for an all-out attack. There had been a few preliminary skirmishes but nothing serious as yet.

Donli undertook the task of setting up barricades at the twilight border. These were huge shields of light but durable metal, arranged in strategic positions, easily movable. And the work at the city went on apace.

Janus and the others directed work at the forges and metal shops. Everyone, men and women alike, who could be spared from the border defenses, were given assignments. Mari was a surprise to the new men. Already she knew the ancient science textbooks by heart, and she thirsted for more knowledge. She was everywhere, directing, helping, learning. She grasped the principle almost at once when Brownell explained:

"Briefly, the atom itself must not be shattered. That has been your mistake. Successive sheathes of electrons must be stripped without disruption of the ultimate atomic structure. That means swift transmutations, not disintegration. Most important of all, the electrons must be propelled along a controlled, directional beam."

Only Ferris was dissatisfied at the hard work. In their quarters, at the end of the first week, he complained:

"What's all this getting us? I thought we came out here to make a fortune! That's the story you gave me, Janus, when you rooked me into this deal."

Janus looked at him distastefully. "Haven't you ever wanted to do a decent act in your life? Lord knows I've done some scandalous things, but these people need our help now and they deserve it!"

"That's not getting back the fortune I sunk into this venture," Ferris grumbled.

"We'll think of that later."

The work was slower than they wished, for it became apparent the Perlac attack was going to materialize any day, any hour. As leader of the defense, the all-out call was left to Donli, who, with his select group, remained at the border constantly now.

And on the tenth day, even before the new pistols had been assembled or tested--the call came. One of the scouts raced into the city with the signal.

* * * * *

Everyone, men and women alike, left their work instantly. Dozens of the electrically-motored surface cars were waiting, and soon they were racing along the road. Within the hour they had reached the twilight zone to reinforce Donli's group.

Each person was equipped with an electric rifle which, at the longer distances, stunned but was not fatal. And there were quantities of atomic grenades. The new Earthmen retained their atomic rifles and neutro-pistols, as they better understood the operation of these weapons and could use them to more advantage.

The attack had not yet come but Donli was expecting it at any minute. Each group took up its assigned position behind a barrier. Mark found himself beside Janus and was glad, for he liked that blustering, red-bearded giant.

"It's going to be hell," Janus promised, peering into the twilight gloom. "We have to wait for them. The Perlacs can come over into our lighter gravity, but their gravity'd be fatal to us!"

Mark nodded. "It means we'll be fighting a strictly defensive battle."

The twilight beyond faded into the darkness of the huge forest, and not a Perlac was to be seen. Not so much as a moving shadow. But they were there, Mark knew, thousands of them; and when they came it would be silently.

And silently they came. Mark's first intimation was the explosion of grenades far down the line, and then he saw them--hordes of Perlacs, heavy of limb, but coming with amazing speed. Most of them were using cross-bows, and Mark realized that some of the shafts were equipped with metal-tipped explosives. Then he was too busy for further observation, as he brought his atomic rifle to bear.

The old style electrics were at work too, all along the line; and the grenades blasted huge gaps in the advancing tide. But still they came, moving now across the lighter zone. Thousands hadn't been an overstatement! The dark tide came rushing over their stunned and dead.

And now those explosive tipped shafts were having effect. Several of them struck a barricade next to Mark, and tore the metal from the foundations. Now Janus, beside him, was bringing the neutro-pistol into play.

Savagely Mark swung his beam in a never-ceasing arc, exulting at the swath it cut before him. Further down, Driscoll, Kaarj and the others were doing the same. Together with the grenades it seemed to stem the tide, but only for a moment.

"Keep it going! Keep it going!" Janus was yelling. "These beams are good for hours!"

The very silence of the attack made it the more terrible. No yells, no screams of fury came from the heavy-furred Perlacs as they littered the terrain by the score.

Then, as suddenly as they had come, they retreated. The seven sweeping beams had done the work well, but in an unexpected manner. Flames were leaping in the lush grass between the defenders and the forest!

"Respite!" Janus yelled. "Ten minutes, maybe. They'll be back when that grass is burned down!"

But there was no resting now. A score of men were dead and twice that many wounded, who had to be carried back from the battle line. Three of the barricades were wrecked, and they strove to get these into place again.

Mark noticed Mari, sweat-grimed and weary, her golden hair streaming down. But she was magnificent still, a tower of strength as she hurried along the line giving aid and encouragement to her people.

"I wonder where the robots are?" Mark suddenly remembered as he worked beside Janus. "If the Perlacs have learned to reactivate those monsters, as Donli thinks--"

"Encouraging, ain't you? As if we're not having a hard enough time as it is!"

And then Mark remembered something else. Remembered so suddenly that he began laughing, a little wildly, and Janus slipped him a light one on the jaw.

"Come out of it, lad! None of that, now--we're not licked yet!"

But Mark had reached to his inner pocket, and brought out his secret flat box. "Remember this, Janus? Good Lord, but I ought to be blasted for forgetting it! You always knew it wasn't a camera--well, now you're going to see it in action!"

"Good, lad! I hope you've got something there. Here they come again!"

* * * * *

This time the Perlacs had massed their forces, and they came in two wide flanking movements aimed at the ends of the barricades.

"Let them get close," Janus passed the word to the men, as they hurried down to the left. "Then give them your grenades--all you've got!"

Grim-faced they waited. Mark once more touched the release stud on his box, exulted as the coils hummed into power.

"Now!" Janus yelled at last, and swept his beam into play. Simultaneously the grenades rained outward. The terrain erupted in geysers of blackened grass and fleshy fragments. But determinedly the Perlacs came, and their cross-bow shafts filled the air.

Despair began to touch the Earthmen now. It was obvious the fanatical Perlacs were going to make this a war to extinction, and there could be but one final result. The Perlacs outnumbered them a hundred to one. If only they could have gotten the new electronic weapons ready in time! Even their grenades were running low now.

Grim-lipped, Mark waited for the next onrush. He passed his neutro to a neighbor and concentrated on his box. Its power had been proven in minor tests, but this would be the maximum!

The wave came. More of them now than before. Mark stepped for a moment into the open, heedless of the shafts. The box, held waist high, looked for all the world like a camera....

But the result was devastatingly different!

The men felt a violent holocaust of air around them, rushing away from all sides. For seconds they couldn't breathe or move! The temperature dropped so suddenly that they were literally frozen where they stood! Then warmer air came pressing in again but still they didn't move, because now they were staring--staring at the miracle.

In a hundred-yard area before their barricade the mass of Perlacs were motionless, many of them arrested in grotesque postures! Others had literally burst outward. But all were dead, and now they began to topple over, like frozen statutes!

Another wave was coming behind, just beyond the area. Now they wheeled and fled for the forest. Quickly Mark adjusted the sights and gave them another burst. The same thing happened. The rush of air, the sudden drop in temperature--and the horde was a mass of frozen corpses. But this time, the box became hot in Mark's hands, burning them severely, and he quickly dropped it.

At the other end of the line the defenders weren't doing so well. The Perlacs had gained that end of the barricade, and the battle was furious and to the death.

"Come on!" Mark raced for that end, followed by the others. But now Mark couldn't use his weapon, for it would mean blasting Earthmen and Perlacs alike!

And then, fantastically, the battle seemed to hang poised.

There came a grinding, shuddering sound. A series of these sounds. The ground seemed to vibrate, and then along the twilight strip came a towering, stalking, fifty-foot shape. One of the robots! It came swiftly, purposefully, huge eyes glaring down--straight for the battle line!