us treasure hunt--not quite what twelve-year-old Chicagoan Delta Wells is expecting when she arrives on Hilton Head Island, South Carolina, to visit her grandparents for the summer! But when Pops tells her that his beloved Island History Museum may be demolished to make room for a golf resort, Delta visits the museum property and discovers a skeleton hidden in the marsh. The bones and a long-secret message from the past send Delta and her younger brother, Jax, on a race to unearth the island's secrets, save their grandfather's museum, and help complete a mission someone started more than 150 years ago.

From the Civil War ruins of Hilton Head, to the site of the H. L. Hunley submarine in Charleston and the University of South Carolina's historic Horseshoe in Columbia, Delta and Jax's vacation is an exciting and educational adventure through history.