All four current leaders of a secret society called the Priory of Sion have been killed, but the last one a Louvre curator named Saunire (Jean-Pierre Marielle) has left an elaborate cryptic clue as to the identity and motive of his killer before dying from a gunshot wound. Part of it involves secret writing that mentions symbology professor Robert Langdon (Tom Hanks) by name. Together with Saunire's granddaughter (Audrey Tautou), Langdon must try to solve the crime while avoiding prosecution for it himself. The mystery involves claims about concealed history, some of which posits that Jesus was married and fathered a child. The faithful may be assuaged to hear that heresy has been played down; Langdon here is envisioned more as an advocate for faith, dismissing much of this scholarship as mere theory. In a movie, it's less of a concern; what is a concern is the endless talk, talk, talk.