They descend. The staircase is new, wet and strewn with dead flowers; the air rising out of the stairwell thick with the smells of excrement and offal. At the bottom, a light burns. They walk towards it and come to a landing and an arched gateway, much older than the stairs. Beyond lie the sewers: a dark canal of stagnant water, flanked by slime-spattered walkways on each side. But their eyes are riveted elsewhere. Dangling from the ceiling, suspended by a rubber string, hangs a bulb of murky, unwavering light. No flame flickers within. It is like an ailing, miniature sun, fetched down from the sky and nailed here by a hangman. When Thomas touches it, it burns his fingertip, then quivers and dances like a hooked fish.

“How will we ever stop her?” Charlie whispers, faced with this new magic.

Livia’s answer is curt. “We must try.”

Thomas is aware of a mixture of shame and relief when he sees her take the lead; of a flare of timid anger when she reaches back and takes hold of Charlie’s hand. Charlie, in turn, stretches his free palm behind himself, looking for his friend’s. Thomas ignores the gesture.

He follows warily, at two steps’ remove.

ф

It isn’t far. A hundred yards of sewer, thrice stripped of its murk by a bulb holding the same mysterious, unflickering light; then an archway opens to a room so long it too feels like a corridor, though it measures a good ten yards in width. The room is built from dark brick, ancient and porous, the mortar worn like a petrified sponge. The ceiling is low above their heads and supported by steel girders, much newer than the brick. A garland of lamps, interconnected by a black line of rubber cable, marks the central axis, from the archway through which they enter, to the far end, hundreds of feet ahead. Beneath these lamps, filling three quarters of the room and only leaving a narrow strip of walking space at either side, lies a series of interconnected pools, tiled in shiny, almost fluorescent green. Each pool is separated from the next by a permeable membrane made of some waxy cloth. Only the top foot of the tiles is visible. The water that stands heavy in the pools beneath is mirror-dark. It is as though a communal baths has been pumped full of ink. All this Thomas sees in passing, following his friends on the long march to the other end. Lady Naylor is there; and Grendel; and Mowgli, tied with belts to a heavy wooden chair.