“Precisely. The conductor without descends. It would be easy for our man to leave the train unseen; it would be easy to catch a train back to Paris or anywhere he pleases. And the crime would be put down as an ordinary train robbery. But for the letter found in Madame’s bag, the Comte would not have been mentioned.”

“It was an oversight on his part not to search that bag,” declared the Commissary.

“Without doubt he thought she had destroyed that letter. It was⁠—pardon me, Monsieur⁠—it was an indiscretion of the first water to keep it.”

“And yet,” murmured Poirot, “it was an indiscretion the Comte might have foreseen.”

“You mean?”