Why is 13-year-old Scout Walker first hiding out in a mountaintop cave and then working in the copper mining town of Bisbee, Arizona disguised as a 16-year-old messenger boy during the autumn of 1896? Her stepfather, Southern Pacific Railroad Detective Pima Gallagher, is up to his ears in problems dealing with inexplicable rail shipments at the same time he's busy searching for the runaway girl. Will Scout be able to maintain her disguise while remaining hidden from her family, or will she become just another victim of a mining accident before Pima is able to locate and rescue her?