There was a swirl of cubical pixels before Luca. It coalesced into the compact form of Dolo. He wasn’t wearing a skinsuit, and his robe was clean. In this place of dirt and rock and fire he was like a vision of an unattainable paradise. He smiled. ‘How are we bearing up, Novice?’

Luca found it difficult to speak. ‘Those troopers who went out of the trench in the first wave. They were children.’ Perhaps some of them had come from the induction camp on New Earth.

‘Think of it in terms of efficiency. They are agile, easy to command. But they are poor soldiers. They suffer higher casualty rates than their adult counterparts, in part because their lack of maturity and experience leads them to take unnecessary risks. And their young bodies are more susceptible to complications if injured. But little has yet been invested in their training.’

‘So they are expendable.’

‘We are all expendable,’ Dolo said. ‘But some are more expendable than others. They will not suffer, Luca: if it comes, death here is usually rapid. And if they see their fellows fall they will not grieve; their childish empathy has been beaten out of them.’ The Virtual floated closer to Luca, studying his face, close enough for Luca to see the graininess of the pixels. ‘You are still thinking this is inhuman, aren’t you? The evolution of your conscience is proving a fascinating study, Novice. Of course it is inhuman. All that matters are the numbers, the rates of mortality, the probabilities and cost of success. This is a statistical war - as wars have always been.’

There was a piercing whistle-like blast over the comms unit. Virtual Dolo popped out of existence, grinning.

A few of the child soldiers scrambled back over the trench’s lip - a very few, and several of them were nursing injuries. More troops came scurrying like files of rats along the trench. Soon there was a double line of them, most carrying hand weapons or tools, peering up at the sky.

For a few heartbeats everybody was still, waiting.

Bayla was beside Luca, as intent as the rest. Luca whispered to her, ‘What was the last thing you did before we left the bio facility?’

‘I sent my daughter a Virtual.’

A daughter. Sons and daughters, like family life in general, were strictly anti-Doctrinal. ‘Where is she?’

‘On New Earth. I told her how as a baby she laughed when she looked at my face. How she slept in my arms, how we bathed together. I told her that when she grows up and wants to know about me she should ask her father or her aunt. Whatever becomes of me, she must never think of herself as a child without a mother. I will always be watching her.’

‘From your place at Timelike Infinity,’ he hazarded.