Father John O'Malley discovers a corpse lying in a ditch beside the highway, but when he returns with the police, it is gone. The Arapahos of the Wind River Reservation speak of ghost walkers - tormented souls caught between the earth and the spirit world, who are capable of anything. Then within days, a young man disappears from the reservation without a trace. A young woman is found brutally murdered. As Father John and Arapaho lawyer Vicky Holden investigate these crimes, someone - or something - begins to follow them. They must stop a killer, explain the inexplicable, and put a ghost to rest.