The Lost Symbol, provisionally known as The Solomon Key, is the third entry in Dan Brown's novel series starring Harvard symbologist Robert Langdon. This time, the story explores the mysteries of the Freemasons and is set in Washington D.C.. Langdon is invited to D.C. by an old friend and mentor (and also not-so-secretly a top-rung Mason), only to discover that he has been an Unwitting Pawn, manipulated by what seems to be a raving lunatic who kidnapped said mentor and now blackmails Langdon into solving the Freemasons' puzzles for him. The final prize in the game is the fabled treasure of Ancient Mysteries, which, Langdon insists, is immaterial but he doesn't have much choice. As if that wasn't complicated enough, the CIA shows up and demands the very same things of Langdon... except that