Langdon is shown the body and a secret message, readable only by blacklight. It contains an out-of-order Fibonacci sequence. Sophie Neveu, a police cryptographer and Saunière's granddaughter, tells Langdon that Fache planted a tracker on him after finding the words, "P.S. Find Robert Langdon" at the end of Saunière's secret message. Fache believes Langdon murdered Saunière. Sophie throws away the tracker, distracting the police while they sneak around the Louvre, finding more clues in Leonardo da Vinci's works. Langdon deduces that Saunière was the grand master of the Priory of Sion.