CHAPTER 30

Security warden Claude Grouard holds Robert Langdon at gunpoint in front of the Mona Lisa, furious because Grouard believes Langdon murdered Jacques Saunière. Grouard tries to call for backup, but the room’s security electronics reduce the radio to static, forcing Grouard to edge toward the doorway while keeping Langdon covered.

Sophie Neveu appears in the dark with an ultraviolet light and identifies herself as Police Technique et Scientifique. Grouard recognizes her name as Saunière’s estranged granddaughter but does not trust her claim that Langdon is innocent. While Grouard struggles to radio for help, Sophie searches the room’s opposite wall and focuses on Leonardo da Vinci’s Madonna of the Rocks.

Sophie reasons that Saunière’s message, “So dark the con of man,” is another anagram and that the painting must be the intended destination. Finding no ultraviolet writing on the floor, wall, canvas, or back, Sophie notices a gold chain wedged near the frame. She retrieves a familiar key marked with a fleur-de-lis and the initials P.S., recalling Saunière’s childhood promise that the key would one day be hers and would open a box of secrets.

Realizing the whole trail was designed to keep the key from the police and deliver it to Sophie, Sophie hides the key and UV light in her pocket. As Grouard nears the doorway, Sophie uses Madonna of the Rocks as leverage: she removes it, shields herself behind it, and threatens to push her knee through the priceless canvas unless Grouard drops his gun and radio. Unable to risk destroying the painting, Grouard obeys.

Langdon and Sophie flee down the emergency stairs, leaving Grouard behind. Langdon carries Grouard’s gun uneasily and asks how Sophie knew to search Madonna of the Rocks. Sophie explains that she missed the first two anagrams and recognized “So dark the con of man” as the third, leading her directly to the painting and the key.