Across the surface of the river—pocked, pitted, rough— ran another kind of roughness, a buckle across the river from one side to the other, a ridge of water, and behind it, water of a different personality: barred, furrowed, a water more like the sea. Change of tide. The line moved imperceptibly upstream, making its way against the hidden force of the current, the river current meeting the tide current, colliding, creating this impasse, this ridge along the surface. Against the face of the ridge small waves broke as if against a wall, flicking and curling all the way along its length, tongues of water trying to mount the incoming pressure of water, but pushed back, back, pushing back into their own pressure, the tide moving in its slow line up past Horselydown Old Stairs, past Suffrance Dock, up past Tower Stairs.

I stopped there. I’d run out of things to say about the change of tide on the Thames. But I skimmed another few pages in the folder and came across something Melissa Lucashenko had said in London about how illiterate people read the world in ways other than through words, and it sparked off a connected idea about Wiseman:

He’d been ashamed, in the grand church, with the columns that vanished high up into shadows, the ceiling out of sight, like God himself—been ashamed of his big fist grasping the feather, the cracked fingertips clumsy, like pieces of wood, as he scratched the nib down and then across where the curate’s white finger pointed, a blank space hemmed around with delicate spidery marks hardly the same species as his own thick lines, with a spot and a spatter where the nib had been crushed too hard against the paper. Solomon Wiseman, the curate had said, pointing. His mark. There, if you please.

He had got ink on his finger, that thick wooden finger. Later, at the Cauliflower, lifting the tankard, he’d seen it and been ashamed all over again, this mockery of an ink-stain, in the same spot on the first finger that the curate himself had had an ink-stain, as if he were pretending to be some other kind of man.

I enjoyed writing the London scenes. I felt I could go on writing them forever. I had the bed of detail from all that research, so I could see in my mind’s eye what I was writing about. It was real. I’d been there, I’d seen it. I even had objects: that bit of roof tile, now on my desk, a big map of early London on the wall. From the real, it was a leap to inventing a world and Wiseman in it, but at least I had something to trigger off those free associations.