Monsieur Van Aldin. I tax him with it, and in the end I get the whole story out of him. I learn where the jewels were handed over, and I learn, too, of the man who paced up and down outside in the street—a man with a venerable head of white hair, but who walked with the light, springy step of a young man—and I give that man a name in my own mind—the name of ‘Monsieur le Marquis.’ ”
“And now you have come to London to see Mr. Van Aldin?”
“Not entirely for that reason. I had other work to do. Since I have been in London I have seen two more people—a theatrical agent and a Harley Street doctor. From each of them I have got certain information. Put these things together, Mademoiselle, and see if you can make of them the same as I do.”
“I?”
“Yes, you. I will tell you one thing, Mademoiselle. There has been a doubt all along in my mind as to whether the robbery and the murder were done by the same person. For a long time I was not sure—”
“And now?”
“And now I know .”
There was a silence. Then Katherine lifted her head. Her eyes were shining.
“I am not clever like you, Monsieur Poirot. Half the things that you have been telling me don’t seem to me to point anywhere at all. The ideas that came to me came from such an entirely different angle—”
“Ah, but that is always so,” said Poirot quietly. “A mirror shows the truth, but everyone stands in a different place for looking into the mirror.”