The Lost Symbol

novel by Brown

Written by

The Information Architects of Encyclopaedia Britannica

Last updated

July 23, 2026

Quick Summary

The Lost Symbol is a 2009 novel by Dan Brown, the third in his Robert Langdon series. The story follows Harvard symbology professor Robert Langdon as he is summoned to Washington, D.C., by his mentor, Peter Solomon, a prominent Freemason. Langdon becomes entangled in a race against time to decipher ancient Masonic symbols and uncover a hidden treasure, all while being pursued by a mysterious antagonist seeking to reveal a powerful secret. The novel delves into the history and symbolism of Freemasonry and explores themes of science, religion, and the power of human thought.1

Summary created from Britannica articles using AI. AI can make mistakes, so verify using Britannica articles.

2 Britannica Sources

Ask Britannica AI about this topic

Britannica doesn't have a full article on this topic, so we've curated a list of our relevant coverage.

Dan Brown
The Robert Langdon series and The Da Vinci Code
…of his tweedy protagonist in The Lost Symbol (2009; TV series 2021), which focuses on Freemasons, and Inferno (2013), which sees Langdon following clues related to Dante’s poem The Divine Comedy in an effort to stop the release of a plague. The latter book was also adapted for the big…
Read More
…of his tweedy protagonist in The Lost Symbol (2009; TV series 2021), which focuses on Freemasons, and Inferno (2013), which sees Langdon following clues related to Dante’s poem The Divine Comedy in an effort to stop the release of a plague. The latter book was also adapted for the big…
Read More