The Lost Symbol:

The Lost Symbol is the third book in the Robert Langdon series by Dan Brown. In this thrilling novel, Harvard symbologist Robert Langdon must decipher a cryptic message that leads him on a dangerous quest through Washington D.C.'s dark history. When his mentor, Peter Solomon, is kidnapped and left with a gruesome object as a calling card, Langdon realizes he must accept the mysterious summons to save his friend's life. This thrilling adventure takes Langdon on a breathless chase through Washington D.C.'s shadowy world of Masonic secrets and never-before-seen revelations, all leading him towards an impossible and inconceivable truth. With its fast-paced action and intricate plot twists, The Lost Symbol is sure to keep readers on the edge of their seats until the very end.