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!”