“You comprehend she was left much alone in California. Her husband was amusing himself elsewhere. Mr. Rolf was handsome, he had an air about him of romance. But au fond, he is very business-like, ce monsieur! He made love to Lady Yardly, and then he blackmailed her. I taxed the lady with the truth the other night, and she admitted it. She swore that she had only been indiscreet, and I believe her. But, undoubtedly, Rolf had letters of hers that could be twisted to bear a different interpretation. Terrified by the threat of a divorce, and the prospect of being separated from her children, she agreed to all he wished. She had no money of her own, and she was forced to permit him to substitute a paste replica for the real stone. The coincidence of the date of the appearance of ‘the Western Star’ struck me at once. All goes well. Lord Yardly prepares to range himself—to settle down. And then comes the menace of the possible sale of the diamond. The substitution will be discovered. Without doubt she writes off frantically to Gregory Rolf who has just arrived in England. He soothes her by promising to arrange all—and prepares for a double robbery. In this way he will quiet the lady, who might conceivably tell all to her husband, an affair which would not suit our blackmailer at all, he will have £50,000 insurance money (aha, you had forgotten that!), and he will still have the diamond! At this point I put my finger in the pie. The arrival of a diamond expert is announced. Lady Yardly, as I felt sure she would, immediately arranges a robbery—and does it very well too! But Hercule Poirot, he sees nothing but facts. What happens in actuality? The lady switches off the light, bangs the door, throws the necklace down the passage, and screams. She has already wrenched out the diamond with pliers upstairs——”
“But we saw the necklace round her neck!” I objected.
“I demand pardon, my friend. Her hand concealed the part of it where the gap would have shown. To place a piece of silk in the door beforehand is child’s play! Of course, as soon as Rolf read of the robbery, he arranged his own little comedy. And very well he played it!”
“What did you say to him?” I asked with lively curiosity.
“I said to him that Lady Yardly had told her husband all, that I was empowered to recover the jewel, and that if it were not immediately handed over proceedings would be taken. Also a few more little lies which occurred to me. He was as wax in my hands!”
I pondered the matter.
“It seems a little unfair on Mary Marvell. She has lost her diamond through no fault of her own.”
“Bah!” said Poirot brutally. “She has a magnificent advertisement. That is all she cares for, that one! Now the other, she is different. Bonne mère, très femme!”
“Yes,” I said doubtfully, hardly sharing Poirot’s views on femininity. “I suppose it was Rolf who sent her the duplicate letters.”
“Pas du tout,” said Poirot briskly. “She came by the advice of Mary Cavendish to seek my aid in her dilemma. Then she heard that Mary Marvell, whom she knew to be her enemy, had been here, and she changed her mind, jumping at a pretext that you, my friend, offered her. A very few questions sufficed to show me that you told her of the letters, not she you! She jumped at the chance your words offered.”