A year ago Thorn's son, Flynn Moss, disappeared into the eco-underground, his only contact with Thorn a series of postcards chronicling his exploits. A federal agent informs Thorn that Flynn had been acting as an informant for the FBI, and when his traitorous acts were discovered, he was summarily executed. The agent proposes a scheme to catch Flynn's killer using Thorn as bait. Thorn, full of rage, accepts the job if only to get his hands on his son's killer.