The book is about a thread in a JFK research forum. It began with a question: "Is this a photo of Oswald leaving the Texas School Book Depository building?"
This picture was a low-quality image from a news film clip (photographer James Darnell) taken seconds after the shots that killed President Kennedy. Nobody knew the identity of the person circled. One researcher, Sean Murphy from Ireland, had studied this figure for a number of years and dubbed him "Prayer Man," due to the posture of his arms.
Who was he?