“Ha,” Kempster grunted in satisfaction.

“I know what a singularity is,” Joshua said. “The point of infinite mass compression. It’s what causes a black hole.”

“It’s what causes an event horizon,” Kempster corrected. “The universe’s cosmic censor. Physics, mathematics—they all break down in the infinite, because you can’t have the infinite, it’s unobtainable in reality.”

“Except in some very specific cases,” Alkad said. “Standard gravitational collapse in stars is a spherical event. Once the core has compressed to a point where its gravity overcomes thermal expansion, everything falls into the centre from all directions at once. The collapse finishes with all the matter compressing into your infinity point, the singularity. At which time its gravity becomes so strong that nothing can escape, not even light: the event horizon. However, in theory, if you spin the star before the event, the centrifugal force will distort the shape, expanding it outward along the equator. If it’s spinning fast enough, the equatorial bulge will remain during the collapse.” Her finger indicated the projected image. “It will form this shape, in fact. And right down at the very end of the collapse timescale, when the star’s matter has all achieved singularity density, it will still be in this shape, and for an instant, before the collapse continues and pulls it into a sphere, some of that infinite mass will project up outside the event horizon.”

“For an instant,” Kempster insisted. “Not fifteen thousand years.”

“It looks as though someone has learned how to freeze that instant indefinitely.”

“You mean like the alchemist?” Joshua datavised to her.

“No,” she datavised back. “These kind of mass-densities are far outside any I achieved with the alchemist technology.”

“If its mass is infinite,” Kempster recited pedantically, “it will be cloaked in an event horizon. Light will not escape.”

“And yet it does,” Alkad said. “From every part of the surface.”

“The vacuum fluctuations must be carrying the photons out,” Renato said. “That’s what we’re seeing here. Whoever created this has learned how to control vacuum fluctuations.” He grinned in wonder. “Wow!”

“No wonder they called it a God,” Alkad said in veneration. “Regulated vacuum fluctuations. If you can do that, there’s no limit to what you can achieve.”

Peter gave her a private, amused look. “Order out of chaos.”

“Kempster?” Joshua queried.

“I don’t like the idea,” the old astronomer said with a weak grin. “But I can’t refute it. In fact, it might even explain Swantic-LI’s jump to another star. Vacuum fluctuations can have a negative energy.”

“Of course,” Renato said. He smiled eagerly at his boss, catching the idea quickly. “They’d be exotic, that’s the state which holds a wormhole open. Just like a voidhawk’s distortion field.”

Samuel had been shaking his head as the discussion ploughed onwards. “But why?” he said. “Why build something like this, what is it for?”

“It’s a perpetual source of wormholes,” Alkad said. “And the Tyrathca said it assists the progress of biological entities. This is the ultimate stardrive generator. You could probably use it to travel between galaxies.”

“Christ, intergalactic travel,” Liol said dreamily. “How about that.”

“Very nice,” Monica retorted. “But it hardly helps us to deal with possession.”

Liol gave her a pained glance.

“Okay,” Joshua said. “If you guys are right about this being an artificially maintained naked singularity, there must be some kind of control centre for the vacuum fluctuations. Have you found that yet?”

“There’s nothing out there except the singularity itself,” Renato said. “Our satellites are covering all of the surface. Nothing hiding on the other side, nothing in orbit.”

“There has to be something else. The Tyrathca got it to open a wormhole for them. How do we do that?”

His neural nanonics reported a new communication channel opening. “You ask,” the singularity datavised.

The cloud’s luminosity remained constant, but its shading had shifted a long way down the spectrum as Louise approached its epicentre. When she walked across the paved plaza outside St Paul’s cathedral every surface was toned a deep crimson. Stone carvings embellishing the beautiful old building cast long black shadows down the wall, ebony jail bars gripping it tightly, squeezing away the last remnants of sanctity.

Her escort pranced around her like insane Morris dancers, inviting her onward with mocking gestures. The snarls of thunder ended as she reached the large oaken doors, leaving an onerous silence. Louise walked into the cathedral.

She took a couple of steps forward, then faltered. The doors closed behind her with a ululation of cold air. Thousands of possessed were standing waiting along the nave, dressed in elaborate costumes from every era of human history and culture, each one completely black. They were all facing her. The organ began to play, blasting out a harsh hard-rock version of the wedding march. Louise put her hands over her ears, it was so loud. All the possessed turned to face the altar, leaving a narrow passage clear down the very centre of the nave. She began to walk down it. It wasn’t a conscious thing, her limbs did as they were commanded by the massed will of the possessed. Her anti-memory weapon fell from numbed fingers after she’d taken the first few steps, clattering away over the cracked tiles.

Ghosts drifted towards her, hands held out to implore. They swept past her as she carried on walking, shaking their heads in sorrow.

The music ended when she reached the front row of the possessed. They were standing level with the cathedral’s transept wings; ahead of them, the floor underneath the vaulting central dome was empty. Iron braziers with foul-smelling fires were lining the walls, their black smoke smudging the pale stonework. She couldn’t actually see the apex of the dome, it was obscured by a pall of grey fug. There was a gallery high above her. Several people leaned on its rail, looking down at her with mild interest.

Her compulsion ended, and she tottered forward.

“Hello, Louise,” Quinn Dexter said. He stood in front of the defiled altar, no part of him visible within the black robe.

She took a couple of unsteady steps. Fear was tightening every muscle, turning her body stiff. She wasn’t even certain she could stand for much longer. “Dexter?”

“None other.” He moved to one side, allowing her to see a man’s body spread-eagled across the altar. “And now God’s Brother has brought the three of us together again.”

“Fletcher,” she squeaked.

Quinn held out an arm towards her and extended a swan-white hand. A claw finger beckoned, granting her permission to approach.

The lacerations and dried blood coating his skin made her afraid. But as she drew closer she saw his muscles were bunched and trembling. An unfamiliar face was contorted with distress, sucking down air in fast pain-filled gulps.

“Fletcher?”

Quinn waved his hand, and the electricity was turned off. The body slumped down onto the stone, panting in shock. Slowly, Fletcher’s face emerged to replace the blooded features. The chains and metal bands securing him dropped away. All of the wounds were banished from sight as his customary naval uniform materialized. He climbed down gingerly from the altar.

“My dearest lady. You should not have come.”

“I had to.”

Quinn laughed. “Your call, Fletch. You can walk out of here with her now if you make the right decision. If not, she’s all mine.”

“My lady.” Fletcher’s face was riven with anguish.

“Why can you walk out?” she asked.

“He’s just got to sign up for the army of the damned,” Quinn said. “I won’t even make him do it in blood.”

“No,” she said. “Fletcher, you mustn’t do that. I came here to warn you all. This has to stop. You have to disperse the red cloud.”