The disastrous outcome of that project all but destroyed us.

After that, human surveillance of Ghost quagma projects was stepped up.

And now it seemed that the Ghosts were at it again.

The Sink Ambassador said, "You do not understand, Jack Raoul."

"Oh, don't I?"

"This is a new program, of great significance. We have every right to progress it, unhindered. Now." It suddenly turned hospitable. "You have traveled a long way. Your doctor is on hand. Perhaps you wish to rest, before returning to the plane of the Galaxy--"

I approached it, holding my arms out wide, my silvered hands raised like weapons. I hoped that the Ghosts -- the Sink Ambassador at any rate -- had studied humans sufficiently to get something out of my body language. "Sink Ambassador, we're not going to let this go. We have to know what you're doing, out here." I pushed my sculptured face so close to its silvery hide I could see my own distorted reflection. "After last time, we're quite prepared to use force."

It seemed to stiffen; I tried to read the thin tones of the translator chips. "Is this some formal declaration of--"

"Not at all," I said. "Our communications are secure, right now. This is just you, and me, out here in the halo of the Galaxy. I simply want you to understand the whole picture, Sink Ambassador."

It hovered in space for a long time, complex standing waves shimmering across its surface. Then: "Very well. Jack Raoul -- what do you know of dark matter?"

Dark matter: a shadow Universe which permeates, barely touching, the visible worlds we inhabit... And yet that image was misleading, for the dark matter is no shadow; it comprises fully nine-tenths of the Universe's total mass. The glowing, baryonic matter which makes up stars, planets, humans, is a mere glittering froth on the surface of that dark ocean.

I let the Ambassador download data into me. In my enhanced vision, huge Virtual schematics overlaid the Galaxy's majestic disc.

"Dark matter cannot form stars," the Sink Ambassador said. "As a result, much larger clouds -- larger than galaxies -- are the equilibrium form for dark matter. The Universe is populated by immense, cold, bland clouds of dark matter: it is a spectral cosmos, almost without structure."

"This is no doubt fascinating, Sink Ambassador, but I don't see--"

"Jack Raoul, we believe we have found a way to construct soliton stars: stellar-mass objects, of dark matter. Such is the purpose of the experiment, conducted here. We will build the first dark matter stars, the first in the Universe's history."

I pondered that. It was a typically grandiose Ghost scheme.

But -- what was its true goal?

And why all the secrecy, from the Xeelee and from us? I knew there must be layers of truth, hidden beneath the surface of what the Ambassador had told me, just as their nuggets of quagma had been inexpertly hidden beneath the regolith of their hollowed-out moon.