I swear to this day that buttlebot jumped.

And so the buttlebot and I found ourselves drifting through a low orbit over the spectacular Xeelee landscape. We watched morosely as the main ship pulled away from the tiny, human-design flitter, and wafted our employer off to the comparative safety of the far-side of one of the planet’s two moons.

My work for the Squeem, roughly speaking, was to do any fiddly, dirty, dangerous jobs the buttlebot wasn’t equipped for, such as to clean out fish tanks and land on hostile alien planets. And me, a college graduate. Of course, the role of humanity at that time was roughly equivalent.

It isn’t that the Squeem — or any of the other races out there — were any brighter than we were or better or even much older. But they had something we didn’t, and had — then — no way of getting our hands on.

And that was stolen Xeelee technology. For instance the hyperdrive, scavenged by the Squeem from a derelict Xeelee ship centuries earlier, had been making that fishy race’s fortune ever since. Tools and gadgets of all kinds, on which a Galactic civilization had been based. And all pilfered, over millions of years, from the Xeelee.

I use the word civilization loosely, of course. Can it be used to describe what exists out there — a ramshackle construct based on avarice, theft and the subjugation of junior races like ourselves?

We began our descent. The dark side of the Xeelee world grew into a diamond-studded carpet: fantastic cities glittered on the horizon. The Xeelee — so far ahead, they make the rest of us look like tree-dwellers. Secretive, xenophobic. Not truly hostile to the rest of us; merely indifferent. Get in their way and you would be rubbed aside like a mote in the eye of a god.

And I was as close to them as any sentient being had ever got, probably. Nice thought.

Yes, like gods. But very occasionally careless. And that was the basis of the Squeem’s plan that day.

We dropped slowly. The conversation left a lot to be desired. And the surface of the planet blew off.

I recoiled from the sudden light at the port, and the buttlebot jerked us down through the incredible traffic. It looked as if whole cities had detached from the ground and were fleeing upwards, light as bubbles. The flitter was swept with shifting color; we were in the down elevator from Heaven.

Abruptly as it had risen, the Xeelee fleet was past. Immense, night-dark wings spread over the doomed planet for a moment, as if in farewell; and then the fleet squirted without fuss into infinity. Evidently, we hadn’t been noticed.

The flitter moved in looser arcs now towards the surface. I took over from the buttlebot and began to seek out a likely landing place. We skimmed over a scoured landscape.

From behind the darkened planet’s twin moons, the valiant Squeem poked their collective nose. “The nova is imminent; please make haste with your planetfall.”

“Thanks. Now get back in your tin and let me concentrate.” I wrestled with the flitter’s awkward controls; we lurched towards the ground. I cursed the Xeelee under my breath; I thought of fish pie; I didn’t even much like the buttlebot. The last thing I needed at a time like that was a reminder that what I was doing was about as clever as looting a house on fire. Get in after the owners have fled; get out before the roof caves in. The schedule was kind of tight.

Finally, we thumped down. Reproachfully, the buttlebot uncoiled its pseudopodia from around a chair leg, let down the hatch and scuttled out. Already suited up, I grabbed a data desk and flashlight laser, and staggered after it. That descent hadn’t done me a lot of good either, but in the circumstances I preferred not to hang around.

I emerged into a bonelike landscape. The noise of my breath jarred in the complete absence of life. I imagined the planet trembling as its bloated sun prepared to burst. It wasn’t a happy place to be.

I’d put us down in the middle of a village-sized clump of buildings, evidently too small or remote to lift with the rest of the cities. In a place like this we had our best chance of coming across something overlooked by the Xeelee in their haste, some toy that could revolutionize the economies of a dozen worlds.

Listen, I’m serious. It had happened before. Although any piece of junk that would satisfy the Squeem and let me get out of there would do for me.

The low buildings gaped in the double shadows of the moonlight. The buttlebot scurried into dark places. I ran my hand over the edge of a doorway, and came away with a fine groove in a glove finger. The famous Xeelee construction material: a proton’s width thick, about as dense as glass wool, and as strong as Life itself. And no one had a clue how to make or cut it. Nothing new; a familiar miracle.

The buttlebot buzzed past excitedly, empty-handed. The vacant place was soulless; there was nothing to evoke the people who had so recently lived here. The thorough Xeelee had even evacuated their ghosts.

“Squeem, this is a waste of time.”

“I estimate some minutes before you should ascend. Please proceed; I am monitoring the star.”

“I feel so secure knowing that.” I tried a few more doorways. The flashlight laser probed emptiness. — Until, in the fourth or fifth building, I found something.

The artifact, dropped in a corner, was a little like a flower. Six angular petals, which looked as if they were made of Xeelee sheeting, were fixed to a small cylindrical base; the whole thing was about the size of my open hand. An ornament? The readings from my data desk — physical dimensions, internal structure — didn’t change as I played with the toy in the light of the flashlight laser. Half the base clicked off in my hand. Nothing exciting happened. Well, whatever it was, maybe it would make the Squeem happy and I could get out.

I took it out into the moonlight. “Squeem, are you copying?” I held it in the laser beam, and twisted the base on or off.

The Squeem jabbered excitedly. “Jones! Please repeat the actions performed by your opposable thumb, and observe the data desk. This may be significant.”

“Really.” I clicked the base on and off, and inspected the exposed underside in the laser light. No features. But a readout trembled on the data desk; the mass was changing.

I experimented. I took away the torch: the change in mass, a slow rise, stopped. Shine the torch, and the mass crept up. And when I replaced the base, no change with or without the torch. “Hey, Squeem,” I said slowly, “are you thinking what I’m thinking?”

“Jones, this may be a major find.”

I watched the mass of the little flower creep up in the light of the torch. It wasn’t much — about an ounce per second, to be exact — but it was there. “Energy to mass, right? Direct conversion of the radiant energy of the beam.” And the damn thing wasn’t even warm in my hand.

I clicked the base back into place; the flower’s growth stopped. Evidently, the base was a key; remove it to make the flower work. The Squeem didn’t remark on this; for some reason, I didn’t point it out. Well, I wasn’t asked.

“Jones, return to the flitter at once. Take no further risks in the return of the artifact.”

That was what I wanted to hear. I ran through the skull-like town, clutching the flower. The buttlebot scurried ahead. I gasped out, “Hey, this must be what they use to manufacture their construction material. Just stick it out in the sunlight, and let it grow.” Presumably the petals, as well as being the end product, were the main receptors of the radiant energy. In which case, the area growth would be exponential. The more area you grow, the more energy you receive; and the more energy you receive, the more area you grow, and…

I thought of experiments to check this out. Listen, I had in my hand a genuine piece of Xeelee magic; it caught my imagination. Of course, the Squeem would be taking the profits. I considered ways to steal the flower…