<P> Sophie Neveu, a police cryptographer, secretly explains to Langdon that she is Saunière's estranged granddaughter, and that Fache thinks Langdon is the murderer because the last line in her grandfather's message, which was meant for Neveu, said "P.S. Find Robert Langdon," which Fache had erased prior to Langdon's arrival . Neveu is troubled by memories of her grandfather's involvement in a secret pagan group . However, she understands that her grandfather intended Langdon to decipher the code, which leads them to a safe deposit box at the Paris branch of the Depository Bank of Zurich . </P> <P> Neveu and Langdon escape from the police and visit the bank . In the safe deposit box they find a box containing the keystone: a cryptex, a cylindrical, hand - held vault with five concentric, rotating dials labeled with letters . When these are lined up correctly, they unlock the device . If the cryptex is forced open, an enclosed vial of vinegar breaks and dissolves the message inside the cryptex, which was written on papyrus . The box containing the cryptex contains clues to its password . </P> <P> Langdon and Neveu take the keystone to the home of Langdon's friend, Sir Leigh Teabing, an expert on the Holy Grail, the legend of which is heavily connected to the Priory . There, Teabing explains that the Grail is not a cup, but a tomb containing the bones of Mary Magdalene . </P> <P> The trio then flees the country on Teabing's private plane, on which they conclude that the proper combination of letters spell out Neveu's given name, Sofia . Opening the cryptex, they discover a smaller cryptex inside it, along with another riddle that ultimately leads the group to the tomb of Isaac Newton in Westminster Abbey . </P>

Where is the holy grail in the da vinci code