Book excerpt: Tom Smiley is a Confederate soldier whose regret for ill-chosen allegiance haunts him not just from enlistment through the horrors of a Union prison but all the way into the afterlife, where he lingers in his ancestral home, unable to shed his shame over fighting to protect slavery--until, one summer afternoon in the early 2000s, two intruders barge into his Virginia house and force him to confront his past.