Something is happening in Sam Travis's backyard, with no clue what that might be. Hikers and campers are disappearing from the Appalachian National Scenic Trail. It's called the AT by locals. The husband of one missing hiker last heard from her on the ninety-mile stretch of the AT that passes through the Berkshire Mountains of Western Massachusetts.

Then, a missing sixteen-year-old girl turns up near the AT bruised and bloody, but alive and missing a chunk of her hair cut right down to her scalp. Environmental Police Officer Sam Travis-an expert tracker-consults with the Massachusetts State Police and the FBI. They must find where the girl was held. She can't remember.

Authorities suspect a connection to similar cases in other states, but the kidnapped girl is the only survivor. Is she the key to catching one or more serial rapists on an escalating multi-state spree? Sam is called in to work with the girl, and to take part in searches spanning three states.

Later, someone discovers a hiker's body in Maine. Her belongings are missing, and a chunk of her hair is missing, too. Travis is called in once more to partner with a feisty FBI behavioral analyst.

Almost a thousand hikers walk the AT's entire two-thousand-mile length each year. How many of the other many disappearances on this dangerous trail fall prey to TWO-legged predators? Will Sam and his friends serve up justice?