Maddy felt like a teacher in front of a class of students. It wasn't a comfortable feeling.

Outside the window was the same scene as before. They were in orbit around the Sun with the rest of the Oort Cloud, but out here orbital velocity was about as fast as a brisk walk. It would be a million years before anything changed in the view.

Ranged around the table, the others looked at the data she had entered into the ship's AI and had displayed on a screen behind her. Reed might have pretended to know what it meant, except everyone knew he didn't. Marshall did pretend, and only made himself look more thuggish and stupid than normal. She was certain Geranium had an insight, given her education, but had to assume she was on a par with the others so that she didn't speak so anyone failed to comprehend.

Marshall put his gun on the table with its barrel pointed at Maddy. She chose to ignore it, although the meaning of the gesture was blatant.

'This is the section of the ghost's database that is of most interest,' she began. She almost started the next sentence with As you can see... but stopped herself in time. 'It's hidden deep, beyond a lot of security that almost melted the ship's AI to get through.' It had also almost melted her brain. 'There's no special security coding on the text itself, however, which is surprising. Almost worrying. But perhaps they figured they were in a section of Zeus that was beyond penetration.'

'What do you mean "worrying"?' Reed floated above the table, perhaps in an attempt to dominate the others.

'Well, a trap still isn't out of the question. It might be we were meant to find this, to lure us somewhere.' She glanced at Geranium, who gripped the edge of the table and stared back. 'Of course, that's a possibility. But maybe not a probability.'

'What do you mean "a section of Zeus?" asked Reed.

Zeus wasn't one AI, she explained. Like the Internet that had preceded it as a compendium of human knowledge, it was a network rather than a single unit, although a network under the strict control of the Syndicate rather than in individual user's hands. Parts of the system could act independently. This file, Maddy believed, was in one of those independent parts. 'The rest of the system might have no idea what this part was doing. It could close itself off in a sub-routine.'

Reed's eyes didn't change as she explained things, but she noticed Geranium nod.

'All right,' said Reed. 'So what is this ship, the Shepherd Moon, supposed to be doing that is so dangerous? You said something about the Moon?'

'I don't know exactly. That is...Well, I know where it's going. And we can make deductions from there.' She touched the control board for the AI and the text on the screen focused in one particular word, which was highlighted in green.

Shiva.

'It's an asteroid.' An inset screen appeared in the corner of the main one, displaying an image of a small piece of rock. 'This asteroid, to be precise. The Shepherd Moon is an asteroid tug.' She let them make the simple connection of ideas.

'Is that the only asteroid name in the data?'

'Well, the only one in this file. There are about fifty thousand or so files on the ghost itself. But I think the intention is to tow the asteroid to an orbit around the Earth.'

The words didn't sound nearly as confident as they did in her own mind. Her next words were even less certain.

'And I think they're going to smash it into either the Moon or the Earth.'

After a moment of silence, Marshall said, 'You think? That's a pretty big thing to think.'

'Quiet,' said Reed. 'Does it say specifically that's what they intend to do?'

'The data doesn't work like that. Without the prime decryption code I can't just "read" the ghost data like it's normal text. There are a lot of pictographs and algebraic equations mixed up with it. It's a metalanguage that is specific to sub-secured Message Stick A57 link protocols.'

'What does that mean?' Marshall couldn't sit still in his seat.

There was no way they could understand the technical side of it, but Maddy nevertheless tried again. 'You have to extrapolate from the given data. It depends on the message patterns being used. In 2432 there was a revision of the logarithmic...'

She stopped. All three of them were staring at her.

'For fuck's sake!' said Marshall. 'Does it say that or doesn't it?'

'Not...I don't...That's what I can make out at the moment.'

Reed asked the AI to magnify the image of the asteroid. It swelled to fill the screen, crowding out the ghost data: a fuzzy grey pear-shaped mass, uninspiring and seemingly innocuous.

'So you're guessing?' he said.

'If I had the prime decryption code—'

'All right.'

Reed floated across the cabin to gaze out of the front window. They watched his back for a while. Maddy drifted over to the table next to Geranium. She smiled at the girl, who nevertheless kept a glum look on her face.

'Life is strange,' said Reed eventually, his face still turned to the stars. 'I was bred on Mars, destined like all other Helots to a life of servitude, and yet I've never done so. I escaped the breeding station, one of those few who manage to do so, and lived in hiding my whole life. And although I've never endured the bonds of slavery, I have been a slave, unable to live as I would wish, fighting against those who would continue this oppression.'

He turned. 'I will fight now, but this time against my own. Freedom comes at a cost, but not at the cost of innocence. Not at the cost of the Moon itself.'

Maddy hung her head and found herself drawing closer to Geranium. She knew what was coming.

'We will go to Shiva. With luck we will be there before the Shepherd Moon and can prevent them using it. I've no idea why they couldn't use just any asteroid. Perhaps they can. If that is the case then we must stop the ship altogether.'

'How do you intend to do that?' Marshall asked. He looked just as dubious as Maddy felt.

'We will find a way.'