Father John O'Malley comes across a corpse lying in a ditch beside the highway. 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 everything. Then, within days, a young man disappears from the reservation without a trace. A young woman is found brutally murdered. And as Father John and Arapaho lawyer Vicky Holden investigate these crimes, someone or something begins to follow them.