She gestures expansively at the building, the cityscape, the night in general. ‘You’re missing the most fundamental understanding of what is happening. Look around you. We are building a new world.’

‘No, don’t start talking about dream landscapes. I want you to tell me what you’ve done in the real world, in waking life.’

‘Oh, stop blathering,’ she says testily. ‘You should hear yourself. Of course I didn’t kill Bernard, or have him killed, or anything like that.’

‘Of course? Well, who did it, then? Daphne was taking pigeon orders from you, so . . . Wait a second. Are you saying Martin sent the pigeon to Daphne?’

‘That is my presumption.’

‘And you thought you’d be next, so you ran away.’

‘Martin had got slightly out of control. You see, the fight with BigSky required dirty tactics. Martin told me that with such deep pockets, BigSky would probably win the IP suit eventually. The courts weren’t going to help us. So it occurred to me that a dreamhacking bot could be instructed to do things that you, for example, would refuse to do.’

‘So you built a murderous robot. What could possibly go wrong?’

‘Martin obviously was worried about Bernard’s ethics getting in the way. It happens a lot with scientists. Martin was concerned that the Dream Police would eventually trace the sleepwalking deaths back to us. He made a tactical decision.’

‘So when you found out Martin was siccing the dreamhacker bot on people, you ran away. Why didn’t you at least warn me?’

‘I could lie and say it was safer for you that you didn’t know, but I’m sure you can see that you would have only hampered me and made it harder for me to get away.’

We stare at each other. The surface of the building is no longer glass. It’s ice. Vapour rises from it in the darkness, and it’s starting to creak.

O says, ‘There are numbers under everything. Under all of this. Under us. All numbers, a heaving sea of them that we’ve got to navigate. I’ve worked with numbers all my life. Sometimes things need to be done, and it isn’t nice but it’s necessary. In the case of Meera, she’s squeamish. The minute she finds out she’s been involved in something illegal or in any way immoral, that will be her finished. She’ll sell out her share to BigSky or give it to one of the universities or the Cat Protection League for all I know, and everything I’ve worked for will have gone to waste. No. This is how it has to be. I knew it from the beginning.’