Pierce appeared unaffected, and continued to watch the fire. Half the map was alight, all of London east of St Paul’s. The fire had caught at the cornice and on spots of the floor. I stamped across the floor, scattering smouldering debris, and aimed high with the water, towards Tottenham, trying to quench the fire at the point that it threatened the ceiling. The jug was exhausted in two large sloshes, the third was a pathetic spray of drops, and while some of the rage was knocked from the fire, it was not exhausted, and its boundaries moved ever outwards.

Increasingly light-headed, I turned to the blanket, first holding it out like a sail to see how wide an area I could smother – not enough. But clutching its upper corners in my fists made me think – it was fireproof, right? I changed my hold, trying to wrap it around my hands as best as I could, and then tried to knock the burning notes from the wall, breaking up the largest patches of the fire and scraping firebreaks, stamping on the flames that fell to the floor. Embers went in my hair and eyes and bit at my cheeks; grey pushed in at the edges of vision. I had to stop, after making what seemed like little difference, to retreat and double over, coughing and retching.

But Pierce had awoken from his trance and had disappeared into the kitchen. He reappeared with a blue plastic mop bucket, much bigger than the jug, even only filled halfway, and directed it at the fiercest points of the fire, across Hackney and Leyton.

Without speaking, we worked together. Pierce hit the greatest concentrations of flame, and I swiped and stamped and snuffed the leftovers and fringes with the blanket. We fought for what felt like an age, though it had been less than ten minutes since he had sparked the lighter, and when we were sure the danger was past and all the windows were open to thin the smoke, we splashed across the sodden floor to the couch, coughing and weeping and spitting.

‘Why did you do that?’ I said, as soon as it was possible to croak out words. ‘You could have killed us.’

‘I’ve been meaning to take that down for ages,’ Pierce said, with a nod towards the map. It was a ruin, two-thirds of it gone, only west London hanging on, damp and sagging from its pins. The cork tiles that had supported the map were blackened and scarred, some no more than charcoal, others fallen away to reveal the shocking, floury white of spalled plaster. A ridge of debris lay along the line of the skirting board, in a wide puddle of sooty water, soaking into a rucked, grimed rug. Despite the open windows, the room stank of smoke, and a haze of particulates perverted the light.

‘The people downstairs are going to be cross,’ I said.