Caroline gave a sniff of disapproval and retired. She returned in a moment or two, ushering in Poirot, and then retired again, shutting the door with a bang.

“Aha! my friend,” said Poirot, coming forward and rubbing his hands. “You have not got rid of me so easily, you see!”

“Finished with the inspector?” I asked.

“For the moment, yes. And you, you have seen all the patients?”

“Yes.”

Poirot sat down and looked at me, tilting his egg-shaped head on one side, with the air of one who savours a very delicious joke.

“You are in error,” he said at last. “You have still one patient to see.”

“Not you?” I exclaimed in surprise.