Irrational treasure

Summary: "Despite their exhausted history teacher's best efforts to get them excluded, middle-schoolers Harry Dunne and Lloyd Christmas join their classmates on a special weekend-long trip to America's capital, Washington, D.C. Shortly after arriving, the boys wander off the guided path at the Museum of American History, where they find a very suspicious-looking security guard seemingly breaking into one of the cases. This doesn't ring any mental alarm bells for Harry and Lloyd, who are instead excited and fascinated by the case's contents, even as the security guard tries to hush them up. Unfortunately, Harry and Lloyd end up setting off the actual alarm bells, and the 'security guard' makes a break for it--but not before dropping a coded map that has certain locations around Washington, D.C. marked with strange symbols. The boys have just one thought: SCAVENGER HUNT! Soon, Harry and Lloyd (and their exasperated classmate Tini) embark on a romp through Washington DC to find everything on this 'scavenger hunt,' all while being trailed by the thief who is after the REAL treasure the map leads to"--