To the casual observer, the Argentine El Secuestador (The Kidnapper) seems to wallow in sordidness for its own sake. The characters are all dirt-poor, and their surroundings relentlessly filthy. The "hero" and "heroine" spend most of their time consummating their romance, most memorably (and audaciously) during a consensual-rape scene in a mortuary. And in another scene, a huge...