“Really; I hadn’t noticed that.”
“Join those two letters to the C and the H which remained after forming the word ‘respondez,’ and you will agree with me that the only possible word is ECHO.”
“What does that mean?”
“It refers to the Echo de France, Lupin’s newspaper, his official organ, the one in which he publishes his communications. Reply in the Echo de France, in the personal advertisements, under number 237. That is the key to the mystery, and Arsène Lupin was kind enough to furnish it to me. I went to the newspaper office.”
“What did you find there?”
“I found the entire story of the relations between Arsène Lupin and his accomplice.”
Sholmes produced seven newspapers which he opened at the fourth page and pointed to the following lines:
1. Ars. Lup. Lady implores protection. 540.
2. 540. Awaiting particulars. A.L.
3. A.L. Under domin. enemy. Lost.