'Don't.'

Dakota stared at the ghost with a puzzled expression. 'Don't what?'

'You were about to apologize. Don't start saying you're sorry for killing me.'

'I wasn't-'

'You made me, spun me out of your memories, and that means I know every thought in your head even before it appears. Now,' he said, leaning down with hands on knees to peer at the component's hull, 'this is interesting…'

Part of her wanted to touch the back of his neck, in case his skin was still warm and soft and carried the same scent as the man she'd known. Instead, she had her ship feed her highly magnified images of the component's exterior. It was studded with millions of extremely miniaturized tach-net transceivers, each one packed with dense molecular circuitry.

This particular component appeared to have a relatively simple function, storing and analysing data from all across the electromagnetic spectrum as well as more exotic phenomena such as gravitic fluctuations and superluminal tachyon drift. If the swarm did have an overarching intelligence, as she suspected, it was almost certainly an emergent property resulting from its sheer complexity.

Dakota lightly touched the fingers of one hand to the component's hull and closed her eyes, tense despite herself. She could hear the whisper of its transceivers, and realized it was still in communication with its brethren.

Perhaps she could tap into that flow, talk directly to the swarm…

She hesitated, drawing her hand back.

'Go ahead,' the ghost prompted. 'It's the opportunity to talk to something that's been alive for billions of years.'

'It's also responsible for creating the caches. The same ones that destroyed the Magi and could still destroy us. What if I… made it angry?'

'Life, Dakota, is a series of opportunities preceded by risks. We have the chance to finally find out what the swarm's ultimate purpose is. So go ahead and try.'

She nodded, and put her fingers once again on the component's hull, listening to the swarm's chatter. What had been unintelligible noise suddenly became clear, and what she learned was so shocking she pulled her hand back with a gasp.

'It's trying to…'

'Re-engineer the universe,' the ghost finished for her. 'A project it doesn't expect to finish until billions of years from now.'

'That's incredible,' she said, 'but how does it help us?'

'Look here,' said the ghost, directing her attention to one particular strand of data. 'There – a way to stop the nova war.'

Once again, she placed her hand against the component's hull. More data came pouring through, almost swamping her conscious mind.

The ghost grinned in jubilation. 'Did you see?'

She nodded. 'I saw it. We've really found something.'

A name, fished out of the depths of the Maker's collective intelligence, and a little more besides. 'Mos Hadroch.' Severn rolled the phrase around his tongue.

They were walking side-by-side through a simulation of the streets of Erkinning, on Dakota's home world of Bellhaven. The winter winds felt so entirely real that she had bunched her hands into fists, pushing them deep inside down-lined pockets, a padded collar pulled up close around her neck and chin. The scent of food and the sound of voices drifted to them from the direction of the city walls, where Grover refugees taking advantage of the daily amnesty had set up a market.

Dakota had murdered Chris Severn while he'd been recovering in an Ascension clinic, cutting out his heart and watching his life-support read-outs flat-line. Another figment of her mind made real, whether she liked it or not – dressed up in the skin of someone who'd died because he'd made the mistake of loving her.

'Whatever it is, it means a lot to the swarm,' Dakota replied. 'It meant something to the Magi as well, but what that meaning is still isn't clear.'

'The Mos Hadroch is a legend,' Josef told her, stopping off at a stall to buy hot tea for them both. 'Or as good as, anyway. There are no surviving records to prove it really existed. It's a weapon, supposedly, built by a predecessor civilization in the Greater Magellanic Cloud.'

Dakota drank the bitter black tea and felt its heat diffuse down her throat. 'It can't be that much of a myth if the swarm wants to find it. We need to try and find out what else it knows.'

Severn frowned. 'You might want to exercise some caution. Trader found out, the hard way, that the swarm can be lethal.'

'There's not enough time to be cautious,' she muttered irritably. 'We need to find out everything we can.'

'Knowledge won't be much use to you if it only gets you killed. The swarm acts like we're beneath its notice, but how can we really be sure?' More days passed, and the starship learned how to decipher more of the data streaming through the captured component's transceivers. For the first time, an accurate picture of the swarm's origins began to form, where before she'd had only disparate fragments of knowledge loosely knitted together with conjecture.

Once the starship learned how to tap into the swarm's senses, Dakota was able to look out on the universe through trillions of eyes.

She eventually discovered that the swarm was very, very old – and not alone. There were others scattered through distant galaxies, having seeded themselves across the face of the universe over vast epochs of time. The origins of this particular swarm dated back to a time when the Earth's sun had barely coalesced from interstellar dust.

It was clear that these swarms maintained contact with each other, despite the vast distances that separated them, by some means Dakota did not yet understand. Although tach-net communications were instantaneous, the amount of energy required to boost a signal so enormously far staggered the imagination. How the swarm obtained the requisite energy was a question that, at least for the moment, might have to remain unanswered.

Mos Hadroch. The term turned up again and again, and it soon became clear that, whatever it might be, the swarm regarded it as a major threat to its primary mission, even while its precise nature remained frustratingly elusive. 'We're getting nowhere in trying to work out what the Mos Hadroch is,' said Dakota. 'I'm going to get in contact with the other navigators back home, see if they can help.'

She was standing with Josef's ghost on the roof of a kilometres-high structure on an otherwise deserted world drawn from the ship's memory. A real-time image of the red giant hung above them, great loops of fiery plasma torn from its surface outlining the flux of its magnetic fields.

He looked at her with a doubtful expression. 'What could they possibly do? For all we know, the Mos Hadroch might be somewhere back in the Greater Magellanic Cloud – or might not even exist anymore. Maybe we should be trying to think of something new.'

'No, you don't understand. The Shoal abandoned a coreship before they left our part of the galaxy. What if there's some clue buried in its data stacks? Or in the wreck of the godkiller back in Ocean's Deep? There are navigators back home who've been flying their own Magi starships for a couple of years now. If I send them everything we know, they might find a correlation within minutes.'

I'm talking to myself, Dakota thought, as she studied the ghost. That's all he is: another part of me that thinks it's someone else. More evidence, if it were needed, that her mind was now unravelling.

'The risk of making contact with home is enormous, Dakota. It's suicidally risky.'

'How do you mean?'

The ghost turned towards her. 'Think about the energy cost of transmitting a signal across seventeen thousand light-years, all the way back to Ocean's Deep. Without enough power, it'll de-cohere into random noise before it even gets there. You're going to have to drain the drive's energy reserves to make sure they receive the message.'