While in Paris on business, Harvard symbologist Robert Langdon is informed that the elderly curator of the Louvre has been murdered inside the museum. Near the body, police have found a baffling cipher. Solving the enigmatic riddle, Langdon is stunned to discover it leads to a trail of clues hidden in the works of Da Vinci - clues visible for all to see, and yet ingeniously disguised by the painter. Langdon joins forces with a gifted French cryptologist, Sophie Neveu, and learns the late curator was involved in the Priory of Sion - an actual secret society. In a breathless race through Paris, London and beyond, Langdon and Neveu match wits with a faceless power broker who appears to work for Opus Dei - a clandestine, Vatican-sanctioned Catholic organization believed to have long plotted to seize the Priory's secret. Unless Langdon and Neveu can decipher the labyrinthine puzzle in time, the Priory's secret - and a stunning historical truth - will be lost forever.