“Don’t like it,” Liol said. “That’s over ten cubic kilometres we don’t know a damn thing about. They could be hiding anything in there.”

“Nothing that’s used very regularly,” Ashly said.

“Yeah, like their biggest-ever weapon.”

“Electrical and magnetic fields are normal,” Beaulieu said. “I’m not registering any large power sources on either side of the disk.”

“Not active ones. The energy for a blast would be stored ready.”

“Ready for what?” Sarha asked.

“I don’t know. We haven’t explored one per cent of this star system, we don’t know what else is lurking around here. Fleets of refugees from other diskcities. Xenocs that live inside the Orion Nebula. Mosdva possessed.”

“Oh, come on .”

“Point taken,” Joshua said. “We need to be cautious.”

“The Oenone can swallow in,” Syrinx said. “Our distortion field will be able to probe the interior of the knot.”

“No,” Joshua said. “I still don’t think we’re ready to give away our biggest advantage yet. Beaulieu, I want constant monitoring of the knot. Any change in its energy state and we jump clear. In the meantime, let’s see what Quantook-LOU’s prepared to tell us.” Before he asked, Joshua cleared the overlay of ship schematics from the sensor image. Tojolt-HI had been bothering him, niggling away for a while now. It wasn’t worry about what they were heading into, he acknowledged, it was the size of the diskcity. He’d been appropriately amazed and impressed with it ever since the sensors had delivered their first image to him. This was different, because their little flight had suddenly put it into perspective for him. They were flying over it, an artefact which was so densely populated it made an arcology appear vacant. Human bitek habitats were fabulous huge entities, but you didn’t fly across them in a spaceship, not for minutes at a time. And they weren’t even halfway to the centre yet.

The visual spectrum sensors showed him a tiny black spot trawling over the burnished sparkle of the glass and foil which made up sunside. Lady Mac ’s shadow, smaller than the width of most web tubes. Many times he’d seen Ganymede’s shadow racing over Jupiter’s dayside clouds, a black blemish smaller than the planet’s cyclone swirls. A moon big enough to qualify as a planet, reduced to its true insignificance by the magnificent gas giant. This was exactly the same.

“We’re going to be at your designated location in a couple of minutes,” Joshua told Quantook-LOU. “I’d like to discuss the terms of the data exchange. After all, neither of us wants this deal to fall apart now.”

“I agree,” Quantook-LOU said. “I will take my escort into this section of Tojolt-HI and secure the information you require. As before, you will be given the indices of the files. If you are agreeable that it is what you want, we will perform a synchronized exchange of our respective information. You will then leave Mastrit-PJ immediately.”

“Fine by me, but won’t you be in danger? This is a long way from Anthi-CL, we can return you.”

“After the exchange I will be the only member of my race to have the information. That makes me more valuable than the sun’s mass in iron. Nobody will harm me. If I was to return to the Lady Macbeth , what guarantee could you give me that you would not simply fly off back to your Confederation, thus removing the knowledge from my race?”

“I would not be able to offer a guarantee that would satisfy you, Quantook-LOU. However, I know nothing of Tojolt-HI. I do not know what is contained within this section behind the web tubes. How do I know that it is not some powerful weapon that can destroy my ship as soon as you have the information you want?”

“This is an old section, its dominion has almost collapsed. Do your sensors not show you that it poses no threat?”

“There is nothing we can see on the surface, but I must know what is inside. I propose to send two of my crew members with you. They will only observe, they will not interfere with your activities.”

“I accept.”

Joshua ended the link. “Ione, you’re on.”

Lady Mac closed slowly on the sunside surface, using ion thrusters to manoeuvre in towards the approximate boundary of the knot. The web tubes below the starship were dead, as Quantook-LOU had requested. He had also asked that Joshua provide a method of crossing the gulf. As a result, the two suited and armoured serjeants were waiting in the open EVA airlock, ready to jet across and secure a tether to the tube surface.

Ione watched the long arched segments of glass grow larger; nothing was visible below the tarnished and pitted surface. Her armour suit sensors could just make out the faint lines of the inner spiral of piping. Lady Mac ’s shadow was expanding and darkening over the glass and foil sheeting as the starship slid inwards. She saw a flickering motion sweep across the darkened glass. A multitude of anfractuous cracks spread out from the rim of the segment as though tendrils of frost were gripping the tube.

“It’s rupturing,” she told the crew.

“Thermal stress,” Liol replied. “It’s our shadow that’s causing it. Don’t forget, that material has never had its heat input interrupted before.”

“Ione,” Joshua said. “I’m locking our attitude . . . mark. You can go over whenever you’re ready.”

The curving glass was seventy metres away from the airlock hatch. The first serjeant disconnected its safety line from the chamber socket and activated the manoeuvring pack.

Attaching the end of the tether was no problem. The cracked glass had come out of the rim of the metal reinforcement hoop, leaving a gap she could loop it through. Once it was done, she moved aside. Joshua wanted the Mosdva to cut their own way in.

The xenocs hauled themselves along the tether using the powered gauntlets they wore on their midlimb hands. There was no subtlety in their entry. One of them simply used a laser to slice a circle through the glass and the piping underneath.

Ione was last in, both serjeants following one of the bodyguard Mosdva. She thought it must have been a long time since the tube was inhabited. The fronds had petrified, then ablated away in the vacuum, leaving a cloud of granular dust clogging the tube. Even with that, it was a lot brighter than the sections they’d toured in Anthi-CL. Without the fluid to shield the interior, the light from the sun was fearsome.

The Mosdva made their way purposefully along to the end of the tube. They used the tarnished plant apertures as grips, which afforded them almost the same degree of mobility as the fronds in a pressurized tube. Ione simply used the manoeuvring packs.

When they reached the end of the tube, one of the bodyguards cut through the airlock hatch with a laser. They moved through the junction and into another tube on the other side, heading into the knot.

As soon as the last serjeant was inside, Joshua used the chemical vernier thrusters to back them away from the sun-side surface. Beaulieu reported that nine small satellites had taken off from across Tojolt-HI. All of them were emitting low-power radar pulses, tracking Lady Mac .

“It looks like Quantook-LOU is heading for the apex of the knot,” Samuel said. “So far he’s staying with the surface tubes.”

“I’m analysing the signals the serjeants’ electronic warfare blocks are picking up,” Oski said. “The Mosdva are transmitting a lot of pulses, most of it’s coming from Quantook-LOU. Fairly high-order encryption, as well.”

“Who’s he talking to?” Joshua asked.

“I don’t think he is. It’s short-range stuff, and there’s no electronic activity in any of the tube systems. I think it’s all being received by his bodyguard. I’m correlating their movements and his signals, and it looks like he’s virtually remote-controlling them. The stuff they’re sending back is completely different, probably sensor feeds so he can see what they’re seeing.”