"The second missive was thought to contain a Playfair cipher suggesting contact with Laboulaye, who'll hide clues before his death. "
"Bức thứ 2 được cho là chứa một mật mã Playfair... ám chỉ liên lạc với Laboulaye, người sẽ che giấu những đầu mối trước khi chết."