Some books, like “The Institutionalist Approach to Public Utility Regulation,” defeat commentary; others, like “Ulysses,” invite it. “Pale Fire,” Vladimir Nabokov’s resplendent rare bird of a novel, comes with its own commentary built in. The novel has four distinct sections: 1) a short foreword by one Charles Kinbote, who has come into possession of a manuscript of the final work by his neighbor and academic colleague, the celebrated poet John Shade; 2) the text of Shade’s opus, “Pale Fire”—“a poem in heroic couplets, of nine hundred ninety-nine lines, divided into four cantos”; 3) a long commentary on “Pale Fire” by Kinbote (of which more shortly); and 4) a thorough, over-thorough index