When world-renowned symbologist Dr. Langdon (Tom Hanks) is called by Parisian policeman Capt. Fache (Jean Reno) to consult on a murder case, the scholar is briefly flattered, then daunted when he learns he is a suspect, owing to a note left by the victim. Along with the victim's granddaughter, cryptologist Sophie (Audrey Tautou), Langdon tries to decipher the message, which begins with the victim's arranging of his own body to approximate Da Vinci's Vitruvian Man. "Symbols," says the doctor early on, "are a language that can help us understand our past." The film reveals various characters' pasts, including the murderer's (a self-flagellating albino Opus Dei monk named Silas [Paul Bettany]), Sophie's, Langdon's, and significant events in history. Robert and Sophie end up on a kind of scavenger hunt from Paris to London, and are tracked by Fache and aided by Robert's colleague, Sir Teabing (Ian McKellen), who claims to be thrilled to be on a "grail quest." The mystery involves a Catholic Church's cover-up -- for thousands of years -- concerning Jesus and Mary Magdalene.