“In any case, during my visit home over the Christmas holidays we debated the problem, and in the end, decided to let the situation stand. My parents would continue with their plans for the bookstore, with my mother working there now as well. They thought that opening immediately after New Year's, which came in the middle of February, would prove auspicious. During the celebrations, they worked late at night to finish the preparations, shelve the books, arrange the furniture.

“No one heard the gun-shots. If they did, no doubt they would have taken them for fire-crackers. Only the following afternoon did it occur to the grocer next door that the bookshop was strangely quiet. He went to see, found the door unlocked, and discovered my parents in the back, dead.

“When the news reached me in Chicago, I left my studies and came home. And I have been here ever since.”

“And the police?” Holmes asked.

The dark, folded eyes behind the lenses regarded him with gentle pity. “The murder of two elderly Chinese servants, in Chinatown? The incident made less of an impression than the police chief's missing budgerigar.”

Holmes nodded, then asked, “After you took over the bookshop, were there any threats or . . . attempts against you?”

“None. Whatever my parents were killed for, it was not the store itself.”

“Had they any valuables?”

“My father, unlike many men his age, was progressive when it came to money. He put his into a nearby bank that was beginning to take Chinese customers—the Bank of Italy, it was called. My father was very impressed with the actions of its owner, Mr Giannini, who went through the fires of hell, very nearly literally, in preserving the savings of his depositors during the days after the earthquake. So no, there was no store of gold under the mattress, no rare painting or Ming vase a collector would desire. No book worth more than a few dollars. And his bill-fold was in his pocket, untouched.”

I spoke up hesitantly. “What about the Tongs? I've heard they are ruthless against those who stand against them.”

“That is true, unfortunately, but unless it was a thing that came up in the few short weeks after I returned to Chicago, no point of conflict had been raised. My father paid what could be called his ‘association fees.' And when I opened the doors of the bookshop, I was never approached for more than I owed.”

“So the murder was because of something they were, or had, or knew,” Holmes mused. “But you never caught a trace of what that might have been?”

“The life of the city closed over them as if they had never been,” the bookseller told us.

After a minute, Holmes rose and stepped out of the back door to slap his pipe out on the stones. He came back inside, locking the door as he spoke over his shoulder.