The Eureka Key
Thomson, Sarah L. When middle school puzzle master Sam and history wiz Martina win a contest for a summer trip across the US, they discover they've been drafted into something vastly more extraordinary. Joining another kid on the trip, Theo, a descendant of George Washington himself, they must follow clues to find seven keys left behind by the Founding Fathers. Together the keys unlock Benjamin Franklin's greatest invention--a secret weapon intended to defend t...