The ornate Victorian street lamps suddenly blink on at the edges of the footpaths, their thick glass globes haloed with tawny light. It is nearly four o’clock, nearly dark. The passing of hours has escaped her. All day she has been caught in the gaping lags between the simplest questions and her ability to respond. Time and again Frieda’s curious, patient face has suddenly materialized out of her thoughts—real, before her, standing in bare feet on the kitchen linoleum, or now, in undone boots—a request for a cookie or a puzzle or a cup of water echoing, empty of meaning, in her head. The clouds roil at the crest of Primrose Hill, concealing the receding western light. It’s there, but hidden, glowing now and then at the edges in slow, observable time.

The sound of car horns ribbons up on the empty air from Prince Albert Road behind her. As the remaining light drains from Primrose Hill, unseen bulldozers scrape a space for the zoo’s new aviary on the far side of Regent’s Canal, cut their belching engines, are silent. Her fingertips, she distantly observes, must have worked the frog over the hard rubber toggle on Frieda’s boot. Frieda is swinging; the back of her red woolen coat comes and goes. With every push on her daughter’s weightless back, the grit beneath Sylvia’s shoe chafes, grinding, eating away the pavement underfoot, the leather of her sole.

The earth is turning. Westward, toward her and the hill she faces, like a mill wheel scooping up days, holding them up to the sun for a moment at their zenith, then turning them out at her, drenching her with unwelcome recollection. As she stands on Primrose Hill, her back to the still and lightless flat on Fitzroy Road, the life she left behind begins to roll forward. All of London, now, falls away before her, sinking and glinting at the skyline; she can feel the inexorable marble turning of the earth beneath her feet.