“I see it with the eyes of the mind, mon ami . So, and only so, could it have happened. Come, let us go back to the house.”

“You want to see Madame Olivier again?”

Poirot gave a curious smile.

“No, Hastings, I want to see the face of the lady on the stairs.”

“Who do you think she is, a relation of Madame Olivier’s?”

“More probably a secretary⁠—and a secretary engaged not very long ago.”

The same gentle acolyte opened the door to us.

“Can you tell me,” said Poirot, “the name of the lady, the widow lady, who came in just now?”

“Madame Veroneau? Madame’s secretary?”