
Chapter 20, in the stairwell
Deciphering the Anagram
As Sophie and Langdon descend the emergency stairwell, Langdon suddenly realizes that the cryptic message 'O, Draconian devil! Oh, lame saint!' is an anagram. He rearranges the letters to form 'Leonardo da Vinci! The Mona Lisa!' This revelation suggests that Saunière's final message is a clue pointing to the famous painting. Sophie is shocked she missed it, as her grandfather was a known anagram enthusiast. They decide to investigate the Mona Lisa.