I had been fighting noisily with my brother, as my father's brand-new Maxwell motorcar had climbed the hill; I had distracted my father at a crucial moment, a fatal moment. I had killed my family, and survived, and in ten years, I had told only two people of my rôle in the disaster: Dr Ginzberg and, five years later, Holmes. She had soothed me, a temporary solution; Holmes had given me an emotional safe-box in which I could lock the knowledge, knowing its shape but no longer consumed by it.

Had I been told that I must return to this place, my first act setting foot in San Francisco would have been to hire a lorry-load of dynamite to blow the entire cliffside into the sea. I still was not certain how I had ended up here, staring at the great grey Pacific. Something Holmes had said, or rather the way he had said it, had made it seem not only necessary, but essential.

“Mary?” Flo's voice made me think she'd said my name more than a couple of times, for it sounded worried, and was accompanied by a hand on my arm. She'd been hovering near me, I realised, ever since we'd left the motor. “Mary, do you want to go now? I don't think we need—”

“No, I'm fine,” I told her. I blinked, and the past retreated a fraction. I was on the piece of ground I hated most in all the universe, ground I should gladly have consigned to the waves below, but it was also merely a piece of precipitous roadway built far too close to the edge of the world.

There was another motor there, as well, I noticed. Some sort of baker's van, although the bow-legged man standing across the roadway from it looked nothing like a baker. As I walked up to him, my first impression was confirmed: Grease, not flour, lay in his finger-nails, boots, and pores. And although he wore a cap, he also held in his hands a grey soft hat, turning it round and round in his blunt, blackened fingers. I stopped at the edge of the cliff near the baker's mechanic (Sunday, my mind processed automatically: no bread deliveries, good day to borrow the van) and looked out across the sea, the expanse of green merging into grey-blue with specks of white here and there, and a trace of mist lingering over the horizon. Then I looked down.