Langdon believes that the Mona Lisa became famous because Da Vinci himself said it was his masterwork and took it with him everywhere he went. Langdon remembers teaching a class to a group of convicts as part of a Harvard program. He explained how the Mona Lisa embodies a balance between the feminine and the masculine. The name Mona Lisa, Langdon thinks, comes from the Egyptian god and goddess of fertility—Amon and L’isa. Some have speculated that the painting is a self-portrait of the artist in drag. This theory would confirm the painting’s message of androgyny, the state of having characteristics of both sexes.
Back in the museum, Sophie and Langdon find blood on the floor and a message composed of six words scrawled on the protective glass over Mona Lisa’s face.
Fache tells Collet that Sophie helped Langdon escape from their grasp. Fache realizes that Sophie and Langdon must still be inside the Louvre and sends half of his men there. The other half he sends to “the only location in Paris where Robert Langdon could find safe harbor”—presumably the American Embassy.
The message on the Mona Lisa is revealed: “SO DARK THE CON OF MAN.” Langdon tells Sophie that the message refers to the Catholic Church’s campaign to rid the world of female-worshipping religions and the Priory of Sion’s opposition to this campaign. A police officer appears in the gallery and takes Langdon into his custody. Sophie hides behind the viewing bench.
Silas takes his cloak off and wraps it around the pole he is using to smash the tile in the Church of Saint-Sulpice. He works quietly because he thinks Sister Sandrine is asleep, but she is watching him from the balcony. When he removes his cloak, the sight of his wounds horrifies her. She cannot understand how Opus Dei can observe such barbarous rituals. Under the tile, Silas finds a stone tablet with the reference number of a Bible verse from the book of Job. Excited, he looks through the Bible, but he finds that something is wrong. The verse reads: “HITHERTO SHALT THOU COME, BUT NO FURTHER.” Sister Sandrine runs back to her room, where she retrieves four telephone numbers given to her for emergency situations.
Claude Grouard is holding Langdon captive. Sophie comes out of the shadows and walks to Madonna of the Rocks, a painting on the other side of the chamber. She examines it with the UV light, but she sees nothing. Her grandfather often showed her this painting, so she is convinced there must be something in it. Moreover, the words he wrote on the Mona Lisa—“SO DARK THE CON OF MAN”—are an anagram for Madonna of the Rocks. When Sophie looks behind the painting, she finds the key decorated with the fleur-de-lis and the initials P.S. wedged into the frame. Thinking quickly, Sophie removes the painting from the wall and holds it hostage, forcing Grouard to put down his gun and release her and Langdon.