"There's another three tanks gone," a note of frustration was clogging Sean's voice. "We're going to lose them all."

"You won't," Julia replied, imperturbable.

"Jesus Christ, the command centre reports a rotational instability. The centre of gravity is shifting in the second chamber."

"Sean, please. Nothing is going to harm New London."

"Yes, ma'am."

"Julia—" Victor began.

Her hand came down on top of his. "It's all right, Victor, really."

"OK." He nodded with obvious reluctance.

Greg wanted to say something, do something to reassure Victor and the people back in the asteroid. Julia's faith was unshakeable, but it was all internal, noncommunicative. He'd believed himself, of course, when the alien had slithered past him, although there was no real way to convey his conviction. Just hang on and pray Julia could deliver, once again.

The emergency capsules' solid rockets had all burnt out, leaving their white and green strobes winking against the backdrop of stars as they deserted New London.

Another burst from the reaction-control thrusters halted the Falcon's drift. They were keeping station fifteen hundred metres out from the mirror spindle. It sliced the starfield in half, an open silver-white gridwork six kilometres long, with the tubular sand duct running down the centre. The foundry plant at the end was a shadowy profile lost in the mirror's umbra, red strobes flashing silently around its empty capsule hatches.

The Falcon rotated around its long axis, bringing the northern hub crater into view.

"Now," Julia said reverently. Her hand was still clamped over Victor's, dainty knuckles whitening.

Greg could see right down into the crater; it was larger than its southern hub counterpart, a couple of kilometres across, a deep conical bite out of the rock. The sides were smooth black glass, streaked with ash-grey rays. It was inert now, but it must have been a good approximation of hell while the electron-compression devices had gnawed it out.

A backscatter of stale light from the big mirror illuminated the sloping walls. The concave floor was three hundred and fifty metres wide, covered with a ribbing of pale metal braces that held down the spindle bearing, a fat gold foil-covered ring containing the superconductor magnets which suspended and rotated the spindle. The sand duct ran straight through the middle of the ring, disappearing into a jet-black bore hole in the crater floor.

"We've lost every datalink into the second chamber," Sean said. "And that includes the foundry plant. But something is tapping the power lines, the load is one hundred per cent capacity. We're having to powerdown some of Hyde Cavern to cope."

"Thank you, Sean," Julia sang. "It's important you maintain the power supply. The drain will only be for a few hours."

Greg couldn't move his attention from the spindle bearing. Intuitive expectation was building up inside him, despite the vestigial neurohormone hangover, the rosy glow before the dawn. Maybe Sinclair wasn't so brain-wrecked after all.

Just outside the spindle bearing ring a small circle of the crater floor cracked open, palpitating like a minor earthquake, then crumbled inwards. Greg's shout died in his throat, his view was inverted, which threw him for a moment; but the floor of the crater was vertical to the asteroid's rotational gravity. The debris should have rolled down the crater wall and fallen out of the lip, instead it had fallen horizontally.

"It's started," he said meekly.

"Where?" Julia hissed.

"Base of the spindle."

A white worm of alien flesh was rising out of the new hole, waxy and pellucid, its tip swaying slowly, as if it was searching. He thought of a maggot clawing out of an apple, then the scale hit him.

"Bloody hell," Victor mumbled.

Julia just giggled.

A second hole fell inwards. Cracks were spreading across the crater floor. The worm's tip began to expand, engulfing the nearby section of the ring bearing. More white tips were reaching blindly out of the ruptured rock.

"What's it doing?" Maria asked.

"Finishing off the second chamber for me," Julia said. "That was part of the deal. I'll have to ship up a lot of hydrocarbons to replace what it's soaked up, but I'll be saving money on the mining operation. Swings and roundabouts, it ought to show a profit in the end."

The white bulk of the alien had completely enveloped the spindle bearing ring. In fact, Greg saw the whole of the crater floor was now a single expanse of undulating white mire. There was no sign of the bracing ribs. A tremor ran up the spindle.

"I hope it won't warp," Julia said in concern.

Greg thought the alien was flowing up the spindle, until he realized it was the spindle itself which was moving. With a lumbrous inexorability that made him wag his head in disbelief, the girders began to slide past the Falcon's nose. The alien was pushing the spindle up out of the crater.

Light and shadows shifted round in the cabin as the huge foundry mirror was impelled away from the asteroid. Nobody had spoken for some time; even Sean Francis had remained quiet. Greg began to relax, soaking it all in; he would never have to buy another round in Hambleton's pub again. I was there.

A white column of alien flesh was mounting below the base of the spindle, guiding it away. He guessed it was about three hundred metres high when the top peeled open, releasing the gold ring of the bearing. It must have imparted a final shove, because he was sure the spindle picked up speed. The white column sank back into the crater. For a moment the floor of the crater was covered by a lake of white flesh, then a dimple formed at the centre and began to deepen.

"You say it's going to hollow out the second chamber for you?" Rick asked.

"Yes. Mine the rock, and refine it. Exactly what Royan dreamed of. You see, he was right. In the end." The grin dropped from her face, and she glanced at Victor for reassurance. He gave her a narrow smile.

All that was visible of the alien was a thin white rim around the base of the crater wall, the rest of it had sunk out of sight, leaving a gaping shaft. A dove-grey globe, three hundred metres in diameter, levitated up out of the centre. The scene reminded Greg of an active-hologram poster he'd bought Oliver for his eighth birthday, time-lapse Earthrise from the Moon. Sedate and unstoppable. They watched it in silence.

"I wonder what that one is," Julia said after the grey globe left the shaft. "It can't be a metal, not with that albedo."

The spindle bearing ring had cleared the top of the crater, with the globe a kilometre behind. A second globe emerged from the shaft, a light metallic blue this time.

"You mean they're all going to be different?" Greg asked.

"Absolutely, yes. Minerals and metals all separated out, with a purity our large-scale refineries can't match. That's something else which will save me a bundle."

A third globe was emerging, another metal one, its mirrorbright surface reflecting warped constellations.

Greg watched the alien disgorging globes for over three hours. Fatigue only affected his body, shutting it down. His mind remained alert, fascinated at the slow carnival of elements riding by outside. The majority of globes were either iron or silica, three hundred metres in diameter. But there were smaller globes, the rarer minerals, dark greens and yellows and blues. Eight batches of them had emerged in clusters at the same time as the ordinary globes, like satellite moons swarming round a gas giant.

It took a while for the end of the procession to register. The last globe, a brick-red colour, which Julia said was probably zircon, had travelled halfway up the crater before he noticed the alien flesh dilating out from the rim to recover the shaft.