The picture on the screen changed. There was no word from the AI. Perhaps it was getting impatient with him. He stared at the picture. Even with part of the deck cut away the shape of the dull footprints was evident. They were long and splayed, with a mark for a back toe; obviously not human and obviously the footprints of dracomen, but was that damning evidence? Anyone who had been to the surface could have carried some of the mycelium away with them. The dracomen had been there longer, so it was more likely to be them.

'Hubris, the dracomen brought the mycelium aboard.'

'Already aware.'

Cormac rattled his fingers on his desk.

What now?

He could try the dracomen again, but his last attempt at communication had tried his patience to the limit. He was sure they were quite capable of speaking with him in some manner, but one of them just sat there and grinned while the other just sat staring at the food dispenser. Perhaps what he needed was face to face, rather than gestures through the viewing window and speech through the intercom.

'Damn it!'

He stood up and headed for Isolation.

As he came from the drop-shaft Cormac saw that Mika was standing before the viewing window to the isolation chamber. She stood in an attitude of deep contemplation, an elbow cupped in one hand and her other hand under her chin. Standing like that she appeared less of a girl. Or was he seeing her differently now? He wondered how old she was. She could be anywhere from eighteen to 300 years. Appearance had not been a way to judge age for the last four centuries. He walked up beside her. She did not acknowledge his presence until he was two paces from her.

'Ah, Ian Cormac.'

'Just Cormac. Something bothering you?'

'No, not really - not bothering me. I'm just intrigued. I did some checking.' She pointed to the floor of the isolation chamber by the far wall. 'You see those?'

Cormac looked across and saw what appeared to be a couple of screwed-up polythene bodysuits. He looked from them to the two dracomen, who were squatting motionless in the middle of the chamber, and noticed that they appeared cleaner, brighter.

'Skins,' he said. 'They shed their skins.'

'They've done it three times since they were put in here. They're regenerating: sloughing off and excreting radiation-damaged cells, and rapidly replacing them.'

'Yes, Hubris told me.'

She glanced at him. 'Did it also tell you that they are also immune to cancer, to replication error?'

'A handy trait, but it is also one we have.'

'Yes, but ours is done by viral or nanomachine repair of our DNA based on the corrected birth blueprint. We still develop cancers and they still have to be cured. This is completely different.'

'I don't know whether or not it is relevant, but, as well as it being proposed that dracoman was one of the race Dragon claimed to represent, it was also proposed that he was some kind of organic machine.'

'We are all organic machines. No, you miss my point… I analysed some of that skin. They are without DNA. They replace cells by direct protein replication. It's been done before, but no creature has ever evolved that method. Far too complex.'

'So they are some kind of machine?'

'If you want to call them that. Philosophy is not my field.'

Cormac felt a twinge of embarrassment. 'I guess that was a stupid thing to say.'

'It was.' She smiled briefly to take the sting away, and went on. 'But these creatures definitely were made in some way. You call them dracomen and in doing that you infer gender, but they are completely sexless: no self-contained method of reproduction. I would say, considering their antecedents, that they were made to serve a purpose, and that purpose is not their own survival and continuation of their genes, as with us; it is Dragon's purpose. They are an alien form of the Golem Series - or any other android for that matter.'

'And what might their purpose be?'

'I have no idea. All I know is that this Dragon built well.'

'There's more?'

'Endless. I could make a lifetime of study out of them.

Their bones are solid; calcium laminated with something similar to tooth enamel, and about twice the size and density of ours. They've got a digestive system which could extract nutrition from a stone.' She turned to him again. 'But, as we know, they take the easy option.' She turned back. 'And their musculature is as dense as old oak. We are lucky Uiey felt no inclination to leave this isolation chamber when we first put them inside. The door would not have stopped them.'

'Perhaps they're different from the one I saw before.'

Cormac remembered his fight in the shadow of Dragon. He had defeated that dracoman quite easily, but perhaps that was what Dragon had wanted. 'Theatrics' are how he had described Dragon's actions to Chaline. It occurred to him that the whole performance had been a cover for other actions; to leave humankind believing Dragon had destroyed itself. Had it been scared, or just a lover of subterfuge?

'Quite likely'

'What… sorry?'

'These are probably different from the one you saw on Aster Colora. Dragon probably makes them to suit its current requirements,' said Mika.

Cormac cogitated for a moment. 'How did they survive the cold?' he asked.

'Now, that is where things get really interesting. They use protein replication, but I have yet to find any kind of template. Their physiognomy will take years to unravel. But… their brain structure is completely different from ours. My theory is that the template is a mental one and that they can alter it at will, within limits. When Thorn said they must have antifreeze for blood, he was probably not far wrong. It would also be interesting to have another look at where they were sheltering.'

'Why? Some evidence there?'

'Just to see how much they ate over the last fifteen months. I bet they ate a phenomenal amount to maintain their body temperatures, and that those corpses we saw were perhaps just a couple of days' supply.'

'Is there anything about them that might indicate their purpose?'

'Nothing really, except maybe their strength. Perhaps they were made to tolerate heavy G… But such strength could pertain to anything.'

'You said the door would not stop them. Just how strong are they?'

'Have you been to the Sparkind quarters?'

Cormac shook his head.

'Well, you remember Gant telling you they had Golem Thirties? Do you know what they are?'

'Cybercorp combat androids. The best.'

Mika pointed at the dracomen. 'These two would be a match even for them.'

'Bloody hell! We should move them to a security section.'

Mika smiled. 'I doubt the security section would hold them either. Anyway, the cell has been armoured since they were first moved in, and there's shutters to come down over this window. Half a second and they end up in a box of ten-centimetre-thick case-hardened ceramal.'

'Will that be enough to—' began Cormac, but was interrupted by Hubris's voice.

'Notification: there will be a slight adulteration of the air supply. This is not a cause for alarm. Counteragents are being spread through all systems. I repeat, there is no cause for alarm.'

Cormac felt something loosen its hold on the inside of his chest; until then he had not quite realized how worried he had been about the nanomycelium. He looked back to the dracomen and saw that Smiler was standing. For a moment he thought food was being delivered. Then he saw that the dracoman was sniffing at the air. He watched, and while he watched he became aware of a bitter metallic taste in his mouth and a pungency to the air that reminded him of the smell from a cold-forge.

The counteragents.

'Chaline works quickly,' he said to Mika, and wondered at the precise meaning of his words.