‘It sounds like an invitation,’ he said at last.

Cold though it was, the street air tasted good after the soggy ashtray of Pierce’s flat. I breathed it deep, and was rewarded with another coughing fit. At least my head cleared a little, enough to remind myself that I had nowhere to sleep tonight. But Tamesis could take care of that, and it was not yet late. Pierce was insistent.

‘I’m surprised you haven’t done this already,’ he said, once more alive with volatile energy. ‘Gone to the end of the rainbow, found the pot of gold.’

‘A notoriously futile and misguided activity,’ I said.

‘You said it’s no more than a couple of streets away,’ Pierce said. ‘You must have been tempted? Don’t you want to find out what’s there?’

‘I haven’t wanted to acknowledge it that much,’ I said. Pierce’s persistent questioning was once again putting me under pressure, and a voice within insisted that I was making a mistake. ‘Even talking about it with you gives it more significance than I would like,’ I continued. ‘I don’t expect to find anything, and I don’t want it to mean anything. If it isn’t fixed in a particular place, it must be centred on me. There’s nothing else to find.’

‘If there’s nothing to find, then there’s nothing to worry about, right?’

I didn’t reply.

‘OK, think about it this way,’ Pierce said. ‘Has ignoring the smoke column made it go away?’

‘No,’ I said.

‘No. It’s been getting bigger and closer, you said. So ignoring it hasn’t worked. Instead, let’s try tracing it, and maybe that’ll be what makes it go away and leave you alone.’

There was logic to that. But I wished I had never mentioned the plume to Pierce, because I saw now that he had co-opted it as the basis of one of his adventures.

‘Well?’ he asked. ‘Which way do we go?’

I kicked the pavement. ‘What are we doing here?’ I asked, not concealing my annoyance.

Pierce shrugged. ‘You came to me.’

True. Why had I done that? If it wasn’t to follow a story, what did I want from Pierce?

‘I’ll tell you what I’m doing here,’ Pierce said. ‘I am pursuing a process. We set out to make something happen – to make an event, a real event, to balance out the incident I invented. A truth for a lie. A true interaction with the city. And we haven’t quite got there yet.’

‘You didn’t get that last night? With De Chauncey?’

He shook his head. ‘No. It was great, it felt amazing. But … I don’t like that Quin set it up. It was staged. Tainted. False.’

‘False? And chasing around an illusion, a hallucination, is truth?’

‘Don’t think of it that way,’ Pierce said. ‘Think of it as … pure. Untainted by outside interference. It’s Quin, see. Quin’s the problem. I thought he was trying to help, in his way – that he wanted to help the city, that he was trying to get it back. But he isn’t.’ He frowned hard, biting into a sour thought.