The Lost Symbol is a bestselling thriller by Dan Brown featuring Harvard professor Robert Langdon. Summoned to Washington, DC, under mysterious circumstances, Langdon discovers that his mentor, Peter Solomon, has been kidnapped. Tasked with deciphering a Masonic code, Langdon races through the city’s landmarks—including the Capitol and the Library of Congress—uncovering secret pyramids, hidden messages, and an ancient mystery guarded by the Freemasons. As he works with Peter’s sister Katherine and confronts the kidnapper, Mal’akh, Langdon unravels a secret that blends history, faith, and human potential, leading to a shocking revelation about power, knowledge, and enlightenment.