Washington DC: Harvard symbologist Robert Langdon is summoned to deliver an evening lecture in the Capitol Building. Within moments of his arrival, however, a disturbing object—gruesomely encoded with five symbols—is discovered. It is, he recognises, an ancient invitation, meant to beckon its recipient towards a long-lost world of hidden esoteric wisdom.

When Langdon's mentor, Peter Solomon— philanthropist and prominent Mason—is brutally kidnapped, Langdon realises that his only hope of saving his friend's life is to accept this mysterious summons and follow wherever it leads him.

Langdon finds himself quickly swept behind the facade of America's most powerful city into the unseen chambers, temples and tunnels which exist there. All that was familiar is transformed into a shadowy, clandestine world of an artfully concealed past, in which Masonic secrets and never-before-seen revelations seem to be leading him to a single impossible and inconceivable truth.