About the booka classic by dan brown, the lost symbol revolves around yet another adventure of harvard symbologist, robert langdon. This one is set in washington d.c. In the united states of america.as langdon is called at the last minute to deliver an evening lecture at the capitol building, an unpredictable thing happens. When he arrives, a hideous object gruesomely encoded with five symbols is discovered at the epicentre of rotunda.recognized by langdon as the ancient invitation that beckons its recipient towards a long-lost world of hidden esoteric wisdom, the object remains a mystery to the others. Things get out of hand when peter solomon, a philanthropist, prominent mason and also robert's mentor, is kidnapped. Robert langdon is now on a quest to save his friend's life by following the mysterious summons of the object.being quickly swept behind the facade of america's most historic city, into its unseen chambers, temples and tunnels, langdon discovers a whole new side to washing