The silence continued as we climbed the stairs to Fast River Imports, as Mr. Zhang unlocked the door and shut down the alarm, and as he switched on lights and took us through to his office. The terra-cotta soldiers on the windowsill seemed suspicious and alert.

A weary hand wave told us to sit. We did, on the glazed ceramic stools, and watched Mr. Zhang unhook a scroll from a nail on the wall. Behind it was a safe door. He twirled the combination, removed papers and cash, and then, with a screwdriver, pried a false bottom from the safe. This was something I’d never seen before. Even Bill raised an eyebrow. Still, neither of us said anything. Nor was a word spoken when Mr. Zhang lifted a velvet box from the hidden compartment and held it out to me.

Until I heard my own disbelieving voice. “You have it?”

And the reply, a command with edges of fear: “Ms. Chin, Mr. Smith. You must never let this knowledge leave this room.”

“You have it? And your cousin doesn’t know?” My voice seemed to be going on without the rest of me, which was unable even to reach out and take the box.

Bill did that. He opened it, peered in, looked up at Mr. Zhang, and turned the box toward me.

On a pillow of blue velvet sat a minute brooch. Eight tiny diamonds circled a diminutive jade disc. No other stones, no grand setting, no filigree or fretwork or chasing. The whole thing wasn’t an inch wide.

“Behold,” Mr. Zhang said. “The Shanghai Moon.”

“This? No. It can’t be. This isn’t-”

“Worth a million dollars. It’s not worth ten thousand. The jade, because of its antiquity, has some value, but as you can see it’s cracked. The diamonds are small, and two are flawed. The only worth of this piece is based on its story, but most collectors, seeing it, would react as you have.”

I took the miniature thing from the box and rested it in my hand. The jade, split along its length, felt cool to the touch, as jade always does; and tiny and flawed though they were, the diamonds sparkled.

Mr. Zhang looked as though he wanted to reach out and grab it back from me, but he didn’t. “The jade Kairong gave Rosalie was not the most valuable stone his family possessed. It was the oldest. Though cracked and small, it was created for a Chen ancestor’s wedding and had been in the Chen family for fifty generations. To Kairong it rep resented enduring family love. The necklace Rosalie chose to dismantle for its diamonds was not the most valuable piece she brought to Shanghai, either. It was the one that meant the most to her.”

I looked up. “How do you know that?”

“Yaakov Corens told me.”

I held the brooch to the light as he went on, “By the time my cousin and I came to America, Lao-li’s obsession with the Shanghai Moon was total. Its legend had grown in the decades since it vanished, both in his mind and in the world of collectors. When I found we were in the same city with its maker, I could not risk Lao-li discovering its truth.”

“Why not? Did you have it by then?”

As though the words were cumbersome, Mr. Zhang spoke slowly. “I have always had it.”

“Then what are you talking about, ‘the decades since it vanished’? It never vanished. You had it!” I thrust out my hand, the brooch sparkling in it. “How could you do that to Mr. Chen? How could you let his obsession ever get started? Why didn’t you tell him? What was the point?”

The silence returned, and lasted so long I was starting to think Mr. Zhang had no answer. And really, what answer could there be? Greed? A family bitterness, a rivalry? Something to lord over his cousin, a way to control him?

Softly, Mr. Zhang spoke. “The seed of the legend of the Shanghai Moon was planted in desperate, dark times. It was watered with tragedy and tended in heartbreak. Public and private. Private and public.

“The truth you hold you in your hand, that small, flawed thing, was meaningless in the face of people’s need-Chinese people and exiled Jews and others besides-to believe something glorious could exist outside the despair and horrors of wartime Shanghai. No, more: could exist amid that despair and horror. From the moment it was made its legend began. That Rosalie would not show it only helped the legend flourish. In whispers, in rumors.

“Those rumors were why, years later, the robbers came for it.” He reached out and took the brooch from me. “But they did not leave with it.”

Mr. Zhang turned the gem in his hand, watching it gleam. “The moment he shot Aunt Rosalie, the robbers’ leader panicked. He commanded the others to retreat. They did. When I reached Aunt Rosalie-as I told you, I was the first-I found the Shanghai Moon’s gold chain broken but the gem still on it, on the floor beside her. I put it in my pocket. I wanted to be the one to give it back to her, when she was well. I wanted to be the one to bring her that happiness.

“But of course there was to be no happiness. Rosalie was dead. When Uncle Paul found her so, and saw the Shanghai Moon gone from about her throat, he wailed and, shocking me, began to curse the gem and those who now possessed it, calling down all manner of misery upon them. They had stolen it, they had killed for it, and now let them suffer all the torments of hell for it. His inconsolable grief and anger frightened me as much as the robbers had. He saw that, and calmed; he embraced me; he asked me to attend to my young cousin while he cared for Grandfather, who was badly hurt. I did so. For many hours I tried to comfort Lao-li with sweets and stories, sang to him, made tea. I brought water for Uncle Paul and tore cloth into bandages. I helped without question in whatever way I was asked. Trying to be good. Trying to hide my guilt and my terror. Because as day turned tonight I’d come to understand that the loss of the Shanghai Moon had killed Aunt Rosalie. Also that punishment was assured to-and deserved by-whoever possessed it now.”

Mr. Zhang paused, sad eyes still on the gem. He seemed to have shrunk.

“Oh,” I said, “but that’s-”

“Yes.” He nodded without looking up. “But I was eight years old.

“Over the next few days, barricaded in the kitchen, Uncle Paul nursed Grandfather while I tried to comfort and distract my cousin. In the dead of night we stole to the garden to bury Rosalie. Uncle Paul chanted prayers and shed tears. And I kept my terrifying secret.

“When Uncle Kai-rong surprised us with his return, he echoed Uncle Paul’s shock, his grief and his curses. Echoed and multiplied them. He forbade us ever to speak of the gem again. And with tears in his eyes he said Lao-li and I were his treasures. A treasure-that was what I wanted to be! Not a thief! Not a cursed killer!

“I thought many times to bury the Shanghai Moon in the garden. To throw it in the river. As though that would remove the curse! Always I was stopped by the thought of Aunt Rosalie. How she had loved it. I hid it among my things.

“In the weeks that followed, I found my young cousin shared my understanding that the loss of the gem had caused Rosalie’s death. Hadn’t Uncle Paul and Uncle Kairong said exactly that? At first we returned to that day over and over, trying to comprehend, but finally, terrified of its power, we made a pact never to speak about it. We kept to our word until my cousin stunned me, weeks later, with an idea spoken casually, as simple truth: Finding the gem would bring his mother back.

“I was a child, at the limit of my understanding, but I knew this was wrong. He went on to confess his greatest fear: that he was not up to the task, and that she could not come back until he accomplished it.

“What I would have given for adult counsel! But I could ask for none. But I also could not bear for my cousin to shoulder this impossible task and the guilt that would accompany his inevitable failure. I was racked with enough guilt for two already! I determined to take the only course I saw. I would show him the Shanghai Moon. I had no doubt this would bring down on my head the punishments the gem’s thief and possessor deserved, but it had to be done for my cousin’s sake.