"By the first post, please," said Quarles, "or by noon Scotland Yard will be busy with the career of Mr. Jacob Hartmann. Good day to you."
It was not until we were in the empty room at Chelsea, Zena with us, that the professor would discuss the case.
"The difficult way was the right one, Wigan," he said. "You are convinced, I presume, that Hartmann has the diamonds?"
"Let me deal with the banker's part in the story first--some theory in the solution, but with facts to support it. Since Leconbridge is an important member of the Conservative Party, and Hartmann has for some time supported the party, I asked myself why Hartmann had not met Lady Leconbridge before. Lord Leconbridge was practically bound to extend him hospitality; that he had not done so, in the only way serviceable to the banker, pointed to the probability that Lady Leconbridge would not know him. Why? Had he pestered her in her theater days and, because she scorned him, had he been responsible for the gossip three years ago? It was evident, I argued, that there was some connection, in Lord Leconbridge's mind, between Hartmann and the diamonds. The banker had done or said something to make Leconbridge suspicious; had suggested possibly, among other things, that his wife could not produce the diamonds were she asked to do so. The real necklace had come into his hands, and he meant to take his revenge."
"But how did he get the jewels?" asked Zena.
"Let me clear up the banker first," said Quarles. "To-day, Wigan, he gave himself away when he said he would know if Lady Leconbridge were wearing paste. Of course he would know, because he had the real stones. No doubt he would have pronounced them paste before the assembled guests--a disclosure which might have proved disastrous to Lady Leconbridge. Whether Hartmann knows the true story of the necklace or not, I cannot say."
"We may conjecture fairly confidently up to a certain point," said the professor. "As Wigan told us the other day, Mr. Dinneford objected to his daughter's engagement to Rupert Lester. Dinneford is a wealthy man, fond of his money; Lester was a spendthrift, and in debt. Lord Leconbridge came to the rescue and paid his debts, after a severe interview with his son, no doubt. I will hazard a guess that the son did not tell his father everything--sons, in these circumstances, seldom do. The creditor left unpaid, some hireling of Hartmann's it may be, began to press the young man--may have suggested, even, how easily he could raise money on the diamonds, which were so seldom worn."