It is one of the eternal laws of the genre that every fictional serial killer must have a grisly idiosyncrasy. Even Cormac McCarthy, a novelist to whose name the phrase "American master" frequently attaches itself, must bow to this rule. Thus Chigurh, the coldly philosophical fiend of No Country for Old Men (Knopf; 309 pages), McCarthy's first book in seven years, carries a signature weapon, a handheld pneumatic stun gun of the kind used on cattle in slaughterhouses. And it's not just distinctive! It baffles investigators, and it's handy for breaking locks. It's like a Swiss Army knife for psychos.
But...