He glanced at the other two. They were deep in conversation, absorbed in each other. Poirot nodded his head in satisfaction, and then leant towards the millionaire, lowering his voice as he did so.
"It is not only for pleasure that I am here, M. Van Aldin. Observe just opposite us that tall old man—the one with the yellow face and the venerable beard."
"Well, what of him?"
"That," Poirot said, "is M. Papopolous."
"A Greek, eh?"
"As you say—a Greek. He is a dealer in antiques of world-wide reputation. He has a small shop in Paris, and he is suspected by the police of being something more."
"What?"
"A receiver of stolen goods, especially jewels. There is nothing as to the re-cutting and re-setting of gems that he does not know. He deals with the highest in Europe and with the lowest of the riff-raff of the underworld."
Van Aldin was looking at Poirot with suddenly awakened attention.
"Well?" he demanded, a new note in his voice.