"What information?" asked the baron. "I don't see...."
Shears copied out the letters and figures in pencil:
C D E H N O P R Z E O—237
"Well?" said M. d'Imblevalle. "That's the formula which you have just shown us yourself."
"No. If you had turned this formula over and over, as I have done, you would have seen at once that it contains two more letters than the first, an E and an O."
"As a matter of fact, I did not notice...."
"Place these two letters beside the C and H which remained over from the word Répondez, and you will see that the only possible word is 'ÉCHO.'"
"Which means...?"
"Which means the Écho de France, Lupin's newspaper, his own organ, the one for which he reserves his official communications. 'Send reply to the Écho de France, agony column, No. 237.' That was the key for which I had hunted so long and with which Lupin was kind enough to supply me. I have just come from the office of the Écho de France."
"And what have you found?"