A dinged-up Grand Marquis rockets through Mexico City traffic, straddling the white line; two young guys inside, very hyper, have a dog gushing blood in the back seat, and, a couple of car lengths behind, some character in a van sticking a pistol out the window and trying to punch a bullet at them. Amores Perros, the most exciting rival of Crouching Tiger, Hidden Dragon in the recent foreign-film Oscar race, begins at a screaming dead run and maintains one kind of intensity or another over the next two and a half hours.

Now, it's safe to tell you that the frenetic chase comes to a metal- and flesh-ripping conclusion within minutes, after which we flash back into the narrative that brought one of the young men--and by all means that bleeding dog--to such an unpretty pass. But to say more is to blunt the shocks of discovery you'll experience if you meet it head-on, with no road map and no checklist of points of interest. That's something a reviewer should always keep in mind, but some movies (cf. Memento) confront the issue more directly than others, and in the good ones--including this one--the shocks aren't just gratuitous, ephemeral "gotchas," but portals opening onto a new dimension of connection and possibility.

Okay, we'll try leaking just a bit more. Amores Perros, pungently translated as Love's a Bitch, comprises three stories of life, love, and aggressively twisted fate in the most polluted metropolis on the planet. They unreel more or less successively, though not necessarily according to linear chronology, and bits and pieces of each crop up in the others.

The first, announced by the title card "Octavio and Susana" after the car crash, focuses on a late-teen (Gael García Bernal) smitten with the wife (Vanessa Bauche) of his brute of a brother, Ramiro (Marco Pérez). The latter is a male-chauvinist scumbag par excellence, and a brainless stickup man besides. When Ramiro's big, good-natured rottweiler reveals an unsuspected talent for ripping out the throats of other canines, Octavio clandestinely appropriates him as his ticket into the world of dogfighting--and the means of scoring the money to run off with Susana.

The second tale, "Daniel and Valeria," involves a honey-blond cover girl with honey-blond legs (Goya Toledo), who breaks up the marriage of a middle-aged entrepreneur (Álvaro Guerrero), only to suffer a Buñuelian comeuppance. She too has a dog, who embarks on a Polanskian odyssey into the netherworld without leaving the luxury highrise into which they have just moved.

Story number three, "El Chivo and Maru," concerns a heroically grufty urban specter (Emilio Echevarría) who is not exactly as homeless as he initially seems, lives with a surrogate family of dogs, and supplements his career as a trash scavenger with a lethal sideline. He's El Chivo, "the Goat," a name justified by his hirsute appearance and omnivorous collecting habits. Who Maru is remains unspecified till their story is well nigh over.

I first heard about Amores Perros when at least two members of the New York Film Festival selection committee walked out on in protest over the horrific fate of the mutts in the dogfight story. (The committee members went back in and, quite correctly, eventually voted for the film.) Let's accept the now-added disclaimer that "no dog was harmed," etc., though animal lovers are duly admonished. What put me off was the relentless grunginess of the first 45 minutes--the characters, events, and every square inch of the poisonous decor--and the dizzy-making handheld camera, which was rarely more than six inches from somebody's facial pores. But as Amores Perros unfolded, and as the cramped oppressiveness of part one was succeeded by the open, light-filled, authoritatively absurdist style of part two and then the sleek noir-suspense mode of the final chapter, I got the big picture and became mesmerized by the power of the interlocking stories. A film is a journey, and Amores Perros really takes you somewhere.

Anyone who's been paying attention has to notice that director Alejandro González Iñárritu and screenwriter Guillermo Arriaga have enrolled in the Quentin Tarantino school of storytelling, but González Iñárritu's own style and vision is already so distinctive and assured in this directorial debut that no one should dwell on that point. This is a breakthrough work for Mexican cinema, and for a bold and powerful new talent.