Investigating the murder of a Louvre curator, Harvard symbologist Robert Langdon and French cryptologist Sophie Neveu find clues painted into a Da Vinci work, inadvertently uncovering a plot involving the Holy Grail and the secret society known as the Priory of Sion.
In 1191, fifteen-year-old Tristan, a youth of unknown origin raised in an English abbey, becomes a Templar Knight's squire during the Third Crusade and soon finds himself on a mission to bring the Holy Grail to safety.