I recounted to her the events of the morning. She listened attentively.

“It all fits in. My letters are the duplicates of hers. It is true that they came by post, but there is a curious perfume impregnating them⁠—something in the nature of joss-stick⁠—that at once suggested the East to me. What does it all mean?”

I shook my head.

“That is what we must find out. You have the letters with you? We might learn something from the postmarks.”

“Unfortunately I destroyed them. You understand, at the time I regarded it as some foolish joke. Can it be true that some Chinese gang are really trying to recover the diamonds? It seems too incredible.”

We went over the facts again and again, but could get no further towards the elucidation of the mystery. At last Lady Yardly rose.