“And where does he stay when in town?”

“At Morley’s Hotel, I believe,” and Hopford wrote that down too.

“Now for heaven’s sake don’t say ‘how small the world is,’ Preston,” Hopford observed lightly as he replaced his notebook in his pocket, “because that is a platitude which makes me see red. I must see Guysburg directly he arrives in London. Certainly we are getting on. I suppose Guysburg didn’t speak about a diamond robbery in Amsterdam from a merchant living in the Kalverstraat, which took place some years ago? The thief was never caught.”

Preston laughed.

“The very thing he did tell me,” he answered. “The stones had been insured by Michaud, to whom the insurance money was paid under protest because the idea had got about that Michaud himself, or some person employed by him, had stolen them.”

Hopford turned to the French woman-detective, and raised his eyebrows.

“You hear that?” he said to her in French. “Isn’t it strange how small—​no, I won’t say it! Mademoiselle was employed,” he addressed Preston again, “on that very case in Amsterdam, and feels as convinced to-day as she did then that Michaud, aided by La Planta, spirited away the stones. Yet nothing could be proved. There were not even sufficient clues to justify the arrest of either of the two men. By the way, I am trying to get mademoiselle to return to London with me, and she hopes she will be able to. Also I have forgotten to tell you that Idris Llanvar is a famous mental specialist practicing here in Paris—​isn’t that so, Llanvar? Years ago he was Johnson’s locum tenens in Shanghai, when Johnson practiced in Hong Kong. It was Johnson who kindly gave me an introduction to him, when he and I met in Jersey. Aren’t you glad, Preston, that Johnson is going to marry Mrs. Hartsilver? I think she is such a charming woman, though I don’t know her very well. But I met the late Henry Hartsilver once or twice—​a typical profiteer, and, I thought, a most offensive person. She was well rid of him. Did you know Sir Stephen Lethbridge?”

Preston looked at Hopford oddly.

“What makes you suddenly ask that?” he said. “What was your train of thought?”

“I had no train of thought, so far as I am aware,” Hopford replied. “But there is a vague rumor in London that someone, a woman, a friend of Stothert’s, holds certain letters written by Mrs. Hartsilver to Sir Stephen Lethbridge, or by Sir Stephen to her, and that this woman is trying to sell them to Mrs. Hartsilver. Incidentally, Preston, your name has been whispered in relation to the affair, which leads me to suspect that Mistress Jessica may not be wholly unassociated with this latest attempt at blackmail. Llanvar had a letter from Johnson yesterday, who is still in Jersey, and in it he alluded to the rumor, but in very guarded language.”