A treasure map. A mysterious explosion. A dangerous quest. In the midst of the Civil War, an orphan boy named Elias lives near Charleston, South Carolina. When his uncle dies and he is left alone, Elias cannot find anyone to trust. Hotly pursued, he embarks on a journey in search of unknown relatives, leading him into the center of some secret Confederate plans. Meanwhile, Johnny and Nahum have arrived at the Union ships blockading Charleston harbor. An unexpected turn of events puts suspicion on Nahum, and Johnny must prove the innocence of his friend. Will Elias find what he is looking for? Can Johnny solve the mystery in time to save his friend-and the lives of countless others?