‘It’s weird, actually, what you say about authenticity following me around,’ I began, not really knowing where to begin. ‘Because for the past few days, I’ve had the impression that I’ve been followed around by …’ I couldn’t finish. It sounded too odd, spoken aloud.

‘By what?’ Pierce’s voice came from the living room.

‘I don’t know,’ I said. ‘I think I must have got a lungful of fumes when we went to Barking, and it’s been messing with my head.’

‘We were equally exposed,’ Pierce said. ‘What’s following you around?’

‘Smoke,’ I said. And as I spoke, my nostrils filled with the smell of burning, unbelievably strong and real.

I clamped my eyes shut. It’s not real, I told myself firmly. It’s a panic attack. I’m stressed, I can’t cope with my circumstances, and my mind tells me to get out as fast as possible. And it creates a reason to do so. That’s what’s been happening. There’s no smoke, it’s an incentive conjured up by the flee reflex in the brain.

The smell was only intensifying. I breathed in hard to try to show myself that the sensations were coming from within, not from the atmosphere. The incinerator stench was overwhelming, and I erupted into a coughing fit.

This was ridiculous. It’s not real, none of it is real.

The kitchen smoke alarm burst into noise, a staccato electronic peal. I was standing directly beneath it, and it was loud enough to cause pain, a spike driven into the head.

I opened my eyes. Smoke was pouring under the kitchen arch in a solid grey river, drawn by the open window over the sink.

‘Shit,’ I said. ‘Shit!’

I lunged into the living room. Smoke swirled across the ceiling and hazed the rest of the room. Its source was the wall-map, where a patch of flame, centred on east London, was licking upwards and outwards. Its bright orange tongues snaked with easy grace through the dry kindling of the notes and clippings. With every passing second a score of new leaves curled, smoked and ignited. Many detached from the map, carrying fire down to the lower portions of the wall and the floor.

Pierce stood with his back to me, staring at what he had done. In his hand was a lighter.

‘Shit,’ I repeated. I twisted on the spot, torn between actions – get Pierce away, or combat the fire? It was immediately, instinctively obvious that he would not help. The blaze covered the entirety of the eastern borough of Newham and most of Barking, and had spread as far north as Walthamstow and Epping; flames were licking soot over the cornice and ceiling, which would soon be burning. Meanwhile the fire spread west, marching through the East End, where Pierce’s overgrowth of annotations was thickest. Canary Wharf and the Isle of Dogs were ablaze, and the inferno had reached Pierce’s home in Mile End – this was what had his attention, watching the fire creep towards the position of his house, even as his real house was on fire.