'For three hundred years, Cawl, I have fought as a domina of the Taghmata. I have served in seven different Exploratory Fleets of the Great Crusade. I have been to the edge of the galaxy and back. During my travels I have faced fourteen hostile xenos species, a hundred and three divergent human civilisations. I have waged war alongside nine Legions, and seen the belligerent arts of the Machine-God tested in every imaginable warzone. The wealth of combat data I possess in this one mind would fill a library of paper books.'

She looked down at him.

'Now why would I let that all go to waste?'

'You betray the Emperor to save your knowledge?' said Cawl.

'You still think I do it to save my life!' she scoffed. 'I live and die at the will of the Machine-God! Knowledge is all. To permit any of it to be lost is a great sin.'

'The Emperor…'

'The Emperor? Horus?' she said. 'Who are they, these Terran upstarts? It does not matter who sits upon the throne. What matters is what resides in the tabernacles of Mars. What matters is what is here, preserved in my minds and my memories.' She caressed her silver cheek with a mechadendrite, a curiously sensuous gesture. 'Kelbor-Hal may be right, we may have a more glorious future at the Warmaster's side. He may be wrong. He is definitely one or the other, he cannot be both. But so long as the knowledge is saved, what does it matter? I might live or I might die. Life is a binary state. It is or it is not. The state of being is unstable and liable to collapse at any time into death, which is eternal.'

'We all die,' agreed Cawl. He glanced at the canisters swinging from her chest.

'We do,' she said. 'Only knowledge persists. All that matters is that while I live so does my knowledge so that it might be added to the sum total of all things known. It is in service to the Machine-God that I go to bend my knee at Horus' throne. If the Emperor Himself came here, I would do the same to Him. The question is, what about you? I kept you alive because I see potential in you. Will you follow me, whoever I pledge my service to, or will you protest your loyalty and die? I can use you, Cawl, but that does not mean I will not end you if I must.'

A triple-pincered claw sprang open. A plasma torch flame burst from the centre. It dipped towards Cawl's face. 'It would be a shame to lose that mind of yours,' said Aspertia. 'If l must kill you, I will probably keep it.'

'I serve the Machine-God!' said Cawl. He mastered his anger and spoke as levelly as he could. 'I serve the Machine-God.'