The flitter burst into a shower of metal rain. The skin of the planet below wrinkled, like a tomato in steam.

And that buttlebot and I rode our Xeelee flower, like surfers on a wave.

It took about twelve hours. At the end of that time, I found I could relax without dying.

I slept.

I woke briefly, dry-mouthed, muscles like wood. The buttlebot clung to my leg like a child to a doll.

We drifted through space. The flower rotated slowly, half-filling my field of view. Its petaled shadow swept over the wasted planet. It must already have been a mile across, and still growing.

What a spectacle. I slept some more.

The recycling system of my suit was designed for a couple of eight-hour EVA shifts. The Squeem did not return from their haven, light years distant, for four days.

I did a lot of thinking in that time. For instance, about the interesting bodily functions I could perform into the Squeem's tank. And also about the flower.

It grew almost visibly, drinking in the sunlight. Its growth was exponential; the more it grew, the more capacity it had for further growth -- I did some woolly arithmetic. How big could it grow?

Start with, say, a square mile of construction material. I made educated guesses about its surface density. Suppose it gets from the nova and surrounding stars about what the Earth receives from the Sun -- something over a thousand watts a square yard. Assume total efficiency of conversion: mass equals energy over cee squared.

That gave it a doubling time of fifteen years. I dreamed of numbers: one, two, four, eight, sixteen... It was already too big to handle. It would be the size of the Earth after a couple of centuries, the size of Sol a little later.

Give it a thousand years and you could wrap up the Galaxy like a birthday present. Doubling series grow fast. And no one knew how to cut Xeelee construction material.

The Universe waltzed around me; I stroked the placid buttlebot. My tongue was like leather; the failing recycling system of my suit left a taste I didn't want to think about.

I went over my figures. Of course, the growing flower's power supply would actually be patchy, and before long the edge would be spreading at something close to the speed of light. But it would still reach an immense size. And the Xeelee hadn't shown much interest in natural laws in the past. We drifted into its already monstrous eclipse; the buttlebot snuggled closer.

This was the sort of reason the Xeelee didn't leave their toys lying around, I supposed. The flower would be a hazard to shipping, to say the least. The rest of the Galaxy weren't going to be too pleased with the Squeem...

These thoughts sifted to the bottom of my mind, and after a while began to coalesce.