After the meal, they took a turn through Union Square, settling onto a bench in the far corner that caught a stray late ray of sunlight. Holmes pulled out his tobacco pouch; Russell closed her eyes and raised her face. A nanny hurried past with her charge in a pram; two boot-boys sauntered through, glancing with professional disdain at the toes of passers-by; a pair of police constables strode the other way, their gazes probing faces, watching for signs of shiftiness.

Finally, Russell stirred. “So, what have you been doing today, Holmes?”

“I have been conducting my own research.”

“Into what?”

“Into your family.”

One bright blue eye opened to look at him sideways. “Really? What aspect of my family interests you?”

“All manner of aspects.”

“Pray tell,” she said, although her voice told him not to.

He ignored her tone, let out a thoughtful cloud of smoke, and said, “Your parents met in the spring of 1895, when your father did the Grand Tour and met your mother at the British Museum.”

“Over the display of Roman antiquities, yes.”

“They married, despite the objections of both sides, little more than a year later, in the summer of 1896.”

“His parents objecting to Mother being a Jew, hers outraged by his being a Christian. Holmes, I've told you all this.”

“And came here, to San Francisco, although his parents had long ago returned to Boston, the Russell family centre. California being, like the Colonies, a place one sent younger sons to try themselves, and with luck to add something to the family fortunes before they came back home to the castle.”

“I thought they'd first come here in 1900, after I was born.”

“Not at all. According to the account books in your father's study, they lived here from 1897 to 1899, before returning to England for your birth. They returned in May 1901. As we heard, they met the Longs eighteen months later, and as your honorary aunt told you, lived here, apart from the period of your brother's birth, until the summer after the earthquake.”

“At which time my mother got nervous about the house falling down around her and took my brother and me back to England. I know.”

“Whatever your mother was nervous about, it did not include houses falling down.”

“What do you mean?”

“According to two of your neighbours, your family moved back into the house ten days after the fire, at which time your mother seemed remarkably light-hearted about the damage, and sanguine about any future catastrophes.”

“Then why would she leave?”

“Precisely what they wondered. And why leave so precipitately, taking only a few bags, and following a loud argument?”

“An argument? My parents?”

“The postman heard it. He said it was unusual. Said, too, that to find your father's motorcar in the drive in the morning was most unusual. You do not remember any degree of discord between your parents?”

“I don't remember them fighting, no.”