Summary: Aboard Teabing’s jet, Langdon again examines the strange text underneath the inlaid rose on the keystone’s box. The language stumps both him and Teabing. Sophie, however, instantly recognizes it as the “mirror writing” she and her grandfather used. The message is English, written perfectly in reverse.
Analysis: Langdon’s earlier speculation that the box’s mysterious sub rosa text was Semitic is revealed to be a red herring in this chapter. A Semitic language (such as Hebrew) might have made sense, given the biblical nature of the Priory’s secret. The truth, however, proves more prosaic: only a mirror—not vowel diacritics, or nekkudot (p. 324)—is needed to decipher Saunière’s message. The connection to Leonardo Da Vinci is a clever one. Da Vinci did indeed practice mirror writing, as the chapter claims. According to the Boston Museum of Science, “Only when he was writing something intended for other people did [Da Vinci] write in the normal direction… People who were contemporaries of Leonardo left records that they saw him write and paint left handed. He also made sketches showing his own left hand at work. Being [left-handed] was highly unusual in Leonardo’s time… No one knows the true reason Leonardo used mirror writing, though several possibilities have been suggested,” ranging from a desire to keep his inventions secret to the more practical desire to avoid smudging of his text (http:www.mos.org/sln/Leonardo/