The mouth of the shaft had shrunk to almost nothing, and now the only light came from the spider-mechs' lamps, which cast sharp-edged pools of illumination against the walls of the shaft as they rushed by. Their conversation lapsed into silence, and Ty guessed Nancy was just as intimidated by the scale of the clade-world as most people were the first time they found themselves inside one.

Before long they reached the crossroads at the asteroid's heart. Someone had directed a spider to nail up a handwritten sign indicating basic directions. Ty braked, and waited for Nancy to do the same.

'We're going into Chamber Two,' he explained, nodding in the direction of Shaft B West. 'It's pressurized, okay? That means we can-'

'Nathan, I know you're dedicated to your work, but get your head out of your a.s.s. Remember I'm the one who writes the daily progress reports. What makes you think I don't already know it's pressurized?'

'Sorry I was just thinking out loud. Another hundred metres, then down the hatch.'

The Atn usually left a basic a.s.sortment of data and tools behind whenever they abandoned a clade-world, but in this case there seemed to be a surfeit of artefacts both physical and virtual. The data was recorded on storage devices built around a core of self-repairing molecular circuitry, the resulting stacks resembling rows of bronzed shields embedded in the walls of dedicated chambers. Most, but not all of the data stored there still remained incomprehensible to human researchers.

The stack chamber was accessed through a pressure seal installed by spider-mechs shortly after their arrival. They pa.s.sed through the airlock quickly, Ty pulling off his helmet once they were inside the chamber. He watched as Nancy did the same, shaking sweat from frizzy blond hair cut into a bob.

The chamber was rectangular, its walls crowded with the ubiquitous spiral-form glyphs. A heap of what might appear to the casual observer as nothing more than blackened junk lay jumbled in one corner. The remains of eight Atn stack-discs were embedded in the wall directly opposite the pressure seal. Each had been carefully and deliberately vandalized; fragments and chunks of the discs lay scattered all around.

Nancy knelt by the pile of junk and poked at it with one gloved finger. 'I don't know, Nathan, we've already been over every inch of this place, and I'll be seriously surprised if we've missed anything.'

Ty pulled off a glove and ran one hand over the ruined edge of a stack-disc. 'We missed one thing.' He nodded towards the pile of junk in the corner. 'That's the remains of an Atn, for a start.'

'Oh.' She stood up and took a step back. 'Are you sure?'

He glanced past her at the twisted remains, which were hardly recognizable as having ever been anything living. 'I ran a tomographic a.n.a.lysis on some trace organic remnants. It's definitely the remains of an Atn, and it's been subjected to extremely intense levels of heat, like something turned the interior of this chamber into a furnace. You remember what Cesar found out about those craters?'

A lot of them were formed relatively recently, and in the same short period of time, right?'

'Exactly It's like something turned up here, killed everything living it found, then disappeared again.'

'All right,' she said, eyeing him with wary respect. 'But if that does turn out to be the case, doesn't it lend itself rather strongly to the notion that if the Mos Hadroch was ever here, it's gone now? And you told me yourself the Atn clades used to go to war with each other. Maybe the ones in this asteroid just happened to lose a fight.'

Ty shook his head violently. 'No, the a.s.sumption a.s.sumption used to be that the Atn must have fought amongst themselves, but the data we got from Merrick makes a strong case for the swarm being responsible for all the damage to clade-worlds we've found in the past.' He stared thoughtfully at the stack-discs for several seconds. used to be that the Atn must have fought amongst themselves, but the data we got from Merrick makes a strong case for the swarm being responsible for all the damage to clade-worlds we've found in the past.' He stared thoughtfully at the stack-discs for several seconds.

'But? I can tell there's a but.'

'There are clade-worlds in even worse condition than this one, back home, but I've never come across stack-discs that looked like they'd been as carefully and deliberately smashed as these.'

She glanced at the melted remains of the Atn, and then back at Ty. 'You think this one smashed them himself, before he got killed?'

'I think it's a fair conjecture. There was something in those discs he didn't want found. Maybe even the exact location of the Mos Hadroch.'

She stared at him like he was an imbecile. 'But if the stacks-discs have been destroyed, how the h.e.l.l are you going to find out?'

'By looking at things differently. For a start, we've mapped out every inch of this asteroid, but there's one pa.s.sageway off Shaft A that's a hundred metres too short.'

She looked at him blankly, and he explained further. 'Look, every single Atn clade in existence follows the exact same internal architecture. It's like they have a blueprint they never deviate from. They only go for bodies of a certain size, between seventy and one hundred kilometres across. Then there are always two central shafts, and exactly the same number of branching pa.s.sageways and chambers, all in the same place and according to a ratio relative to a particular asteroid's dimensions.'

He grabbed her by the shoulders and grinned. 'When Cesar called in, I'd already gone to check out that pa.s.sageway and I'd bet my life it's capped with a false wall.'

'You think there's something hidden behind it?'

'Why not? There's gear back on the frigate that can tell us if I'm right.'

Nancy carefully extracted herself from his grasp. 'Well, that's great. We can have Martinez send over some explosives so we can blow it open.'

'First we need to know how thick the false wall is. Too thick and we'll need a lot of explosives, except that could collapse the pa.s.sageway on top of us and maybe destroy whatever they hid beyond. No,' he shook his head, 'first we image the pa.s.sageway to get some idea what's back there. We can even drill a hole through if necessary. But we need to get started on this now, Nancy. Right now. now.'

She stared at him for another moment, then set her mouth in a firm line and opened a comms link to the Mjollnir Mjollnir ' 's bridge. bridge.

Ty felt a weight lift off his shoulders; it seemed they were finally getting somewhere.

Less than an hour later, Curtis Randall and Anton Swedberg technical specialists were manoeuvring new equipment down the shaft and into the suspect pa.s.sageway, with the help of nearly a dozen spider-mechs. A large drill mechanism, mounted on a tripod and a.s.sembled from a kit, had been set up next to the false wall, its three legs firmly secured to the floor. The drill bit itself was hidden from view behind a flat plastic shield.

'Got word from Perez,' Ty heard Randall say over their shared comms. 'Martinez is coming online in a couple of seconds. Something's up.'

Ty glanced behind himself and saw two spider-mechs delicately directing a package down the pa.s.sageway towards the false wall, casting deep shifting shadows as they pa.s.sed under a string of lights positioned along the ceiling. 'What is it?'

'Anton says he spoke to Tibbs on the bridge, and Mjollnir Mjollnir ' 's picking up a local increase in background tach-net noise as well as gravity flux waves in the tach-net continuum. Looks like the swarm just arrived.' picking up a local increase in background tach-net noise as well as gravity flux waves in the tach-net continuum. Looks like the swarm just arrived.'

Ty felt a sudden panic flood him. They were running out of time.

Get a grip, he thought angrily. He glanced over at Nancy, unpacking gear beside him, and caught the look of alarm on her face, even through her visor. he thought angrily. He glanced over at Nancy, unpacking gear beside him, and caught the look of alarm on her face, even through her visor.

'If we're lucky, it's only a few advance scouts,' Randall added, as the two spiders came to a halt. Ty turned to them and began unstrapping the packages they carried. 'I'm sorry to be, you know, the bearer of bad news.'

Ty nodded, feeling numb. 'Then we have to-'

'Forgive me for eavesdropping, Mr Driscoll,' said Martinez, 'but I couldn't help overhearing.' Ty glanced down and noticed that the small, gold-coloured bar representing the Mjollnir's Mjollnir's commander had manifested in one corner of his visor. 'The situation's starting to look pretty desperate from where I'm standing.' commander had manifested in one corner of his visor. 'The situation's starting to look pretty desperate from where I'm standing.'

Ty could hear murmured conversations and background noises on the bridge. 'How far away are they?' Ty asked immediately. 'A star system's a big place, Commander, so we might have as much as a couple of days before they figure out exactly where the asteroid is.'

'Mr Driscoll, if the swarm gets here before we leave, it isn't going to matter a d.a.m.n whether you find anything behind that wall or not.'

'I know that, sir,' Ty replied carefully. 'But all I really need is a couple of hours. You know how important this is.'

The background hiss faded for a moment, and Ty guessed Martinez was consulting with Dan Perez, one of his senior officers.

'Okay, here's what I propose,' said Martinez when he came back online. 'The instant the swarm appears, the Mjollnir Mjollnir jumps straight out of this system regardless of whether you're still on that rock or not. The same goes for everyone else who stays there, and the choice is strictly voluntary. I have to think of the crew.' jumps straight out of this system regardless of whether you're still on that rock or not. The same goes for everyone else who stays there, and the choice is strictly voluntary. I have to think of the crew.'

'n.o.body's under any obligation to stay here and help me if they don't want to,' Ty replied, glancing over at Nancy and Curtis, 'but I know I can do it a h.e.l.l of a lot quicker if I have some help.'

'What about the spiders?' asked Martinez. 'Have you considered whether you could run the entire operation from the bridge?'

'No,' Ty said straight away. 'Look, the spiders help a lot, but they're no good for fast, delicate work. They're far too slow and clumsy for what we need to do here, and it'll end up taking much longer than it should, if we have do the entire thing by tele-operation.'

'Nathan's right,' Ty heard Nancy say. 'The spiders are fine for this kind of work only if there's no time constraint.'

'Yeah, I agree,' said Curtis. 'The more of us down here who know what we're doing, the faster we get everything done and get back out. The last of the detectors is now in place, so we should be able to pick up a video feed straight away.'

'That's fine, Curtis,' Martinez replied. 'But every a.n.a.lysis says we don't need more than two people down there, so I want you and Anton back here on the frigate. Nancy and Nathan, I spoke to Cesar. He's going to remain on the surface with a fast launcher. Just don't take one second longer than you have to.'

'No problem.'

Martinez cut the connection.

'Detectors?' asked Nancy.

'Muon detectors,' Curtis explained. 'We stuck them around the surface of the asteroid. They pick up traces of decaying cosmic-ray particles, so we can build up a picture of whatever's inside there.'

Ty nodded. 'Did you bring the screens?'

Curtis pa.s.sed a rolled-up video monitor over to Ty, who opened and smoothed it against one wall, holding it flat there while Curtis retrieved a hammer from a spider's toolbox and nailed the monitor to the stone at all four corners.

Ty stepped back and studied the chiaroscuro of greys that appeared on the monitor a few moments later, quickly resolving into a map of the asteroid's tunnels and chambers.

'There,' Ty said excitedly, pointing one gloved finger at a shape like a fat grey worm. 'That's our pa.s.sageway, right there.'

Nancy stepped up beside him and peered at the shifting image. 'There really is something behind that wall, isn't there?' she murmured, clearly fascinated.

Curtis leaned in beside them and touched the screen with one gloved finger. 'There are some dark shapes on the other side. Can you see them?'

Ty felt a burst of elation and fought to stay calm. 'I see them, yes, and I don't think this is going to be as difficult as I thought.' Glancing at Curtis, he said, 'Martinez is expecting you and Anton back at the Mjollnir. Mjollnir. You'd better get going.' You'd better get going.'

Curtis nodded, and Ty could see the other's desire to remain there warring with his fear of the approaching alien threat. a.s.suming they got out of this alive, they'd all of them have stories to tell for the rest of their lives.

Curtis nodded with resignation and stepped back. 'Nathan, Nancy good luck to both of you. I'll see you back on the ship.'

Ty nodded and watched for a moment as Curtis retreated back down the pa.s.sageway, before turning his attention to the drill rig. He touched a b.u.t.ton, and the drill's bit began to cut into the wall in total silence. All he really had to do now was set the parameters, step back, and let the machine perform.

It did not take long before the pa.s.sageway around them began to fill with clouds of grey-black dust as the device did its work. Ty watched the drill's readout, indicating how deep it was penetrating; it had cut through nearly fifty centimetres of rock before it signalled that it was no longer encountering resistance. Nancy watched as he pulled the drill free, and together they stepped up to the narrow opening left behind.

Nancy withdrew a long, narrow silver tube from a suit pocket and carefully slid it inside the freshly drilled hole. After a couple of seconds she pulled it back again.

The tube had contained a mobile security device modelled on a terrestrial insect, complete with a minuscule propulsion system optimized for zero-gee. After she'd repocketed the now empty tube, Nancy pushed a couple of high-intensity glow-sticks through the hole until they slid through into the other side, falling slowly under the asteroid's minimal gravity.

'Okay,' Nancy said breezily, stepping over to the screen. 'Let's see what we'll see.'

She now reset the screen to show whatever the insect-machine's lenses were picking up on the other side of the wall. After a few moments they saw a huddled shape about fifteen metres from the false part.i.tion. Other than that, the other side looked deserted.

'That's it?' murmured Nancy, unable to mask her dismay.

'Doesn't matter,' said Ty, fighting back his own growing doubt. 'There's still something back there valuable enough that someone wanted to seal it up for a very long time.'

Nancy peered at the screen. 'I can't be sure, but it looks like it might be the body of another Atn.'

A warning light blinked up inside both their visors and a priority transmission came through from Martinez. 'Nathan, Nancy; the gravity flux readings just about went off the chart during the past couple of minutes.'

'What does that mean?' asked Ty, baffled.

'It means there are even more swarm-components than we thought. Hundreds of the d.a.m.n things. You should seriously reconsider returning to the ship now. now.'

'No way. There's definitely something here, but it's going to take time to get to it. You need to hold on until then.'

'I thought you might say that. I already talked to Cesar, and he's going to stay topside for at least the next hour. Any longer than that, and every risk a.n.a.lysis the ship can come up with says our chances of getting out of here alive drop off dramatically. Good luck.'

Martinez signed off and Ty let out a slow, steady breath. 'You're okay with that?'

Nancy shrugged, and a faint smile tugged the corners of her mouth upwards. 'I guess I'll have to be.'

Under normal circ.u.mstances, Ty might have spent days meticulously scanning the sealed-off corridor before carefully and laboriously dismantling the false intervening wall. The present circ.u.mstances required a more direct approach, for which purpose shaped charges had already been spidered over from the Mjollnir. Mjollnir.

They first drilled several more holes at different points on the rock wall. Meanwhile a computer feed from the Mjollnir Mjollnir ' 's bridge hovered in one corner of Ty's visor, showing a schematic of the system, along with a constantly updated animation based on the estimated location of the swarm. bridge hovered in one corner of Ty's visor, showing a schematic of the system, along with a constantly updated animation based on the estimated location of the swarm.

Every time one of the alien machines jumped through super-luminal s.p.a.ce, it sent a faint ripple rushing through the super-luminal continuum like an undulation moving across the still surface of a pond. The Mjollnir Mjollnir ' 's defensive systems mapped these ripples as they occurred in real time, and it was immediately clear that the swarm was spreading out to cover the whole system. Ty thought of the sheer volume of s.p.a.ce they were trying to encompa.s.s, and wondered if the swarm really had a chance of finding them any time soon. defensive systems mapped these ripples as they occurred in real time, and it was immediately clear that the swarm was spreading out to cover the whole system. Ty thought of the sheer volume of s.p.a.ce they were trying to encompa.s.s, and wondered if the swarm really had a chance of finding them any time soon.

Once the drilling was finished, Ty carefully slid the charges into place, one to each hole, then followed Nancy back towards the relative safety of the main shaft. The spiders moved ahead of them, spreading out into the shaft beyond.

Ty and Nancy then moved to either side of the pa.s.sageway's mouth. He tried to ignore the trickle of sweat he could feel rolling down one cheek, and glanced over at her s.p.a.cesuited figure.

'Ready?' she asked, one finger hovering above an arm-mounted control.

Ty nodded.

'Okay Three, two, one, boom. boom.'

There was no sound, of course, but Ty's imagination filled it in all the same. Seismic taps on the surface immediately fed details of the resulting tremor back to him through his suit's readout. Barely a moment later, a thick column of grey smoke and grit came billowing out of the mouth of the pa.s.sageway, spreading into the main shaft.

Nancy was now barely visible through the dust and swirling grit. 'Can't see anything on the visuals,' he heard her say.

'Too much debris for that,' he replied. 'Let's go see if it worked.'

They sent a couple of spiders in first, in case there were any really big chunks of debris still bouncing around inside the pa.s.sageway, then both followed it in, moving carefully.

The explosives had worked better than Ty might have hoped, and yet the pa.s.sageway immediately beyond what remained of the false wall differed little from the section that preceded it. The threat of disappointment lurked like a leaden weight in the pit of his stomach. But they finally got a good look at what they'd previously glimpsed only as an indistinct grey shadow.

It was indeed the body of a single Atn but nothing else.

'Are you getting this?' Nancy asked. Ty looked round to see her turning her head slowly from side to side as she moved through the opened-up section of the pa.s.sageway. He a.s.sumed she was transmitting live video to the Mjollnir' Mjollnir's bridge.

Ty kneeled by the Atn's bulky corpse and brought his suit's light up close to it, studying the intricate, stylized whorls and sigils engraved into its carapace. As far as he could see, there was nothing whatsoever unusual about it.

'Well, I guess that's it,' he heard Nancy announce over the general comms link. 'This is all there is.'

'Just hold on a minute,' Ty snapped irritably. 'We've barely had a chance to look around yet.'

'Come on, Nathan, there's nothing here. Let's face it, we tried and we failed.'

Ty struggled to control the quiver in his voice. 'Nothing here except for an Atn that the rest of its clade went to such enormous time and trouble to hide. Does that make sense to you?'

'I don't know. Maybe it's simply a burial chamber, and this was one of their leaders. That would explain the story of the Mos Hadroch, wouldn't it? Maybe that thing's what the Atn regarded as a king or hive-queen?'