The Captain turned on him. “Ballantine, get off my back, will you? All I care about is the schedule I’ve got to meet.” She looked at something approaching over Ballantine’s shoulder, and she smiled faintly as she continued: “If you can prise that thing out of the wreck in the next twelve hours, fine. Otherwise don’t bother me.” Her smile widened.

Ballantine opened his mouth to complain further — but never got the chance. A massive arm closed around his waist and lifted him, wriggling, into the air.

The Captain just kept on grinning.

“Come on, Ballantine!” Krupp roared, carrying him to the wreck. “Let’s see whether this thing of yours really works.” And he flicked the switch over and held Ballantine with two hands over the gravity disc. The other men watched expectantly. “Go for it, Krupp!” Ballantine just hung there like a limp doll.

With one mighty boost, Krupp hurled the little scientist straight up.

Now Krupp is a big man. Under normal gravity he could have launched Ballantine’s weight through — what? A couple of yards?

Under one percent of gee, Ballantine soared up two hundred yards. He took about thirty seconds to drift back down; he had to tumble like a clumsy snowflake into a circle of laughing faces.

He stumbled away, brushing past me. His eyes were bright, like ice.

After ten hours we’d just about finished. Most of the men were in their cabins, cleaning up. I stood on the ship’s ramp, peering up at the eclipse of one egg-shaped star by another.

Ballantine emerged from the ship and stood with me, gazing out in silence. After a while I decided to be sociable. Lethe, we were all a long way from home. “Did you get your nullifier free from the wreck?”

He shook his head angrily. “What a waste. And it works on a completely new principle.”

“Really?” I asked, already regretting opening my mouth.

“Did you know that gravity is actually made up of three forces?” he lectured. “There’s the positive force Newton discovered — and two extra, short-range forces called the Yukawa terms. Yukawa was a twentieth-century scientist.

“One Yukawa is positive and the other is negative, so they cancel each other out. Overall, two positives and a negative leave you with one positive, you see…”

His voice got higher, sharp with bitterness. I began to wonder how I could get away. “What the Xeelee artifact does is to nullify the Yukawas. The control switch has two settings. The first neutralizes the positive Yukawa, so that leaves the negative and just one positive — nothing, to within one percent.

“But the other setting doesn’t turn the device off, as I thought at first. Instead it — neutralizes… the…”

He tailed off, staring at the wreck. Only Krupp was still out there; as a nominal penalty for his prank the Captain had set him the chore of dumping the instruments’ data into the desk.

Krupp moved behind a blackened rib. Ballantine glanced at me, his face empty, then ran jerkily down the ramp towards the wreck.

Intrigued, I stayed to watch. Ballantine walked to the center of the nullifier disc and turned the two-way switch. Then he hoisted up the data desk’s one percent weight and set it on his shoulder. He posed like a parody of Krupp, grinning coldly—

— until Krupp himself came back into view. The big man stared, amazed. Then he strode up behind Ballantine and gave him a shove that sent him sprawling. The desk tumbled in the air; Krupp caught it neatly.

Ballantine hauled himself stiffly to his feet and brushed purple dust from his suit.

Krupp laughed at him. “Leave men’s work to the men,” he said harshly. “Turn that gravity thing off, Ballantine, and I’ll carry the desk back to the ship.”

Ballantine knelt and deftly turned the switch to its second setting.

Krupp gasped; his knees buckled. With a grunting effort he straightened up. I watched, bewildered. Ballantine approached Krupp and stared up into his face. “What’s the matter, big man? Can’t hold a little weight?”

Krupp looked as if he might drop the desk — but while Ballantine taunted he had to stand there, legs shaking.

Something was wrong, I realized. Shouting for help I ran to the wreck; I brushed Ballantine aside and turned the switch. As the weight lifted from him, Krupp sighed. His blood-swollen face smoothed over and he fell back into the dust.

It took three of us to carry him back to the ship.

The Captain spent a long time grilling Ballantine, but she came away frustrated. What was there to find out? Krupp had hoisted one load too many, crushed a few vertebrae—

The Captain filed a report, and Krupp started to learn to use crutches.

I spent a long time thinking it all over.

We lifted off, and I found myself standing once more with Ballantine, this time at a port. We watched the planet recede. I began: “You were saying?”

His bony head swiveled towards me.

“On the ramp,” I prompted. “Remember? You said that switch wasn’t on-off…”

He turned away, but I grabbed one sharp-boned shoulder. “You see, I’ve worked it out. You said there were three gravity forces, two positive and one negative. One setting of the switch canceled out the positive Yukawa, leaving zero overall.

“But the other setting didn’t switch the device off. It canceled out the other Yukawa. The negative one. And that left two positives…”

Ballantine grinned abruptly, showing crooked teeth.

I went on, “The first time you turned that switch you watched the data desk fall twice as fast as it should have done. That was your clue… And that’s how you got Krupp. The data desk suddenly came down on him at two gravities—”

“I had to abandon the nullifier on the planet,” he cut in harshly. “So you’ll never know for sure, will you, Gorman?” His head rotated and his pale eyes locked onto mine.

I knew he was right.

I had nothing else to say. I broke the stare and walked away. Ballantine stayed at the port, teeth bared.

The only law governing the squabbling junior races of the Galaxy was the iron rule of economics.

The second Occupation of the worlds of mankind was far more brutal than the first.

Because there were so few of them, the species called the Qax weren’t naturally warlike — individual life was far too precious to them. They were instinctive traders, in fact; the Qax worked with each other like independent corporations, in perfect competition.

“The Qax enslaved mankind simply because it was an economically valid proposition,” Eve said. “They occupied Earth because it was so easy — because they could. They had to learn the techniques of oppression from humans themselves. Fortunately for the Qax, human history wasn’t short of object lessons…”

PART 3

ERA: Qax Occupation