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. But when a postcard arrives unlike the others, a call for help, Thorn jumps into action, setting off for North Carolina. But before Thorn arrives, he's intercepted by a federal agent who informs him he's too late--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. Little by little, however, Thorn discovers that nothing he's been told is true, and the trap they're setting isn't for Flynn's killer, but for his partner, a woman who proves more daring and dangerous than any Thorn's ever met.