P.S. Find Robert Langdon

P.S. Find Robert Langdon is the fourth and most damning line of the message Jacques Saunière wrote on the parquet floor of the Grand Gallery as he lay dying from a gunshot wound. The first three lines—a scrambled Fibonacci sequence, "O, Draconian devil!" and "Oh, lame saint!"—had already baffled the police. But the postscript, written in the same invisible, alcohol-based fluorescent ink and visible only under ultraviolet light, turned the investigation upside down. Captain Bezu Fache photographed the complete message and then deliberately wiped the final line clean before Robert Langdon arrived at the crime scene, keeping it hidden as a trap to see how Langdon would react.

Discovery and Concealment

Sophie Neveu, a cryptographer with the DCPJ and Saunière's granddaughter, discovered the full message when she examined the crime-scene photographs sent to her department. She brought a printout to the Grand Gallery and showed it to Langdon in the men's room, revealing the line that Fache had suppressed. The postscript read simply: "P.S. Find Robert Langdon." Sophie explained that the initials P.S. were not an abbreviation for "postscript" but her grandfather's pet name for her—"Princesse Sophie"—making the message a personal communication directed at her. The inclusion of Langdon's name, she argued, was not an accusation but a dying instruction: Saunière wanted his granddaughter to find the Harvard professor.

Narrative Role and Significance

The postscript functions as the story's central plot engine, transforming Langdon from a witness into a fugitive and forcing him to ally with Sophie. It also serves as a key piece of evidence that Fache uses to justify his surveillance cachée—a covert interrogation technique in which the police pretend to consult a suspect while secretly recording him. The message's cryptographic structure—a simple anagram embedded in a larger code—reflects Saunière's lifelong passion for word games and puzzles, which he shared with Sophie. The postscript's true meaning, that Saunière wanted Sophie to find Langdon because he trusted the professor's judgment, only becomes clear later when Langdon realizes that his editor had sent Saunière a manuscript about goddess worship and the sacred feminine, a topic that directly concerned the Priory of Sion's secrets.