On August 23, 2011, the East Coast of the United States trembles and shakes from a 5.8 magnitude earthquake. The earthquake's epicenter is near Mineral, Virginia, not far from where Bailey Fish and her friends live. Bailey's middle school is quickly evacuated, and when she reaches home at Lake Anna, she's surprised by what she finds. The earthquake's damage uncovers hidden treasures from the Civil War era, and a book about Henry Box Brown, a slave born in 1815 near the earthquake's epicenter. Henry Brown's story of shipping himself to freedom in a wooden crate captivates Bailey and her neighborhood friends, who attend Earthquake School until the public schools reopen. The treasures are not the only surprises for Bailey. An early-morning knock on her grandmother's door announces unexpected visitors.