I shivered uncontrollably. It was the dream that I’d had, the dream that Birgitta must have had, too. Which can’t work unless the dream was viral – or this too was obeying the retrospective memory theory. I turned over the pad to reveal another sketch, this time depicting a scene under an old car. Someone in the picture was trying to reach for a flashlight they’d dropped, the light revealing the profile of a face that was, in Birgitta’s past words: ‘of inspiring intrigue’. It was me. But it wasn’t just me, it was the recent memory of me. This morning, when we’d met under the Buick. Birgitta had lost almost everything, but retained the complex eye-to-hand coordination of the artist she once had been.

‘I fooled myself I’d met your husband,’ I said in a quiet voice, ‘over at HiberTech. Guy named Webster. Has a beard and drives a golf cart. One of the redeployed.’

She looked blankly about, but made no hint of either understanding what I had said, or of even being conscious of her surroundings. I handed her a pen several times, but the only time she grasped on to it, she let it drop almost immediately. She was drawing from memory – a human photocopier. A complex trick, but a trick nonetheless. I felt a sense of hopelessness rise within me. Even if I could slip her past Toccata’s policy of retiring all nightwalkers and somehow explain satisfactorily why she was still alive, HiberTech would just disassemble what remained of her mind and redeploy her as a menial worker, a mindless drone. I don’t think she would have wanted that. No, I had to do what I should have done that morning.

I went into the kitchen to fetch her more water, but when I came back there was another picture on the pad: a man in a golf cart with a beard. Not from life, as the golf cart was different, as was the corridor. But that didn’t matter right now. There was something more important going on.

She had processed what I’d said.

‘Shit,’ I said, ‘you can understand me.’

I snapped my fingers in front of her face but she didn’t so much as blink.

‘There will always be the Gower,’ she said in a quiet voice.

‘Okay, then,’ I said, sitting down next to her, ‘my name is Charlie Worthing, I’m a Novice Consul – well, Deputy now, I guess – and to everyone else you’re simply a Tricksy nightwalker and as good as dead, but I know that you’re not. Can you even begin to explain to me where you think you are right now?’