Structured as a triptych of intersecting narratives, this film centers around a seemingly inconsequential dog named Cofi, whose injury in a dogfight sets off a dramatic chain of events that converge in a Mexico City car crash. "Octavio and Susana" follows Cofi's teenage owner, who enters her into the dogfight to raise the money to run off with his brother's pretty young wife. "Daniel and Valeria" is the story of a middle-aged businessman who leaves his family to be with a gorgeous model who is tragically altered in the crash. In "El Chiva and Maru," we see the life-altering effect the accident has on an eye-witness, a former revolutionary-turned-assassin. This moral portrait of human behavior--a world where violence begets violence--is director Alejandro Gonzalez Inarritu's look at the people (and dogs--there over more than a million strays) that populate the world's largest, most populous city. See "Opening Friday" for theaters.