Book excerpt: When a squad of combat engineers blows up a decrepit building in the waning days of the Vietnam War, they set off an obsession in a CIA agent, which leaves a decades-long trail of blood coast to coast across the United States. Private investigator Harley Napoleon, hired by the widow of one of the engineers, gets snared in a web of lies and threats as he tries to solve the puzzle of what happened back then and winds up at odds with a present-day mobster, congressman, and general.