The young hero of The Speed of Light is an aspiring writer in provincial Spain in the 1980s, dreaming of burning success, searching for a real story to tell. Out of the blue he is offered the chance to work in a in a Midwestern university and soon he is in the United States, living a happy, carefree life, working and writing.

Little does he know that his burgeoning friendship with the Vietnam Vet Rodney Falk, a man of few friends and strange ways, will influence the course of his entire life, or that he will become obsessed with unravelling the mystery at the heart of Rodney's life.

Why do people sometimes ridicule and sometimes fear Rodney? Why does he shun the world? Why does he accept and befriend the narrator? What really happened at My Khe?

When the young writer's own life takes a terrible twist many years later, Rodney may be the only person in the world who can save him.