Not that Arriaga's preoccupation has hampered his career. Amores Perros won a series of international awards, making Arriaga and the film's director, fellow countryman Alejandro Gonzales I?arritu, celebrities in the Spanish-speaking world. The film's success paved the way for 21 Grams, which won the pair international acclaim, put Mexican cinema on the map, and marked the first time that a Mexican writer's work had been filmed in the US.

Arriaga says that although success is 'not a bad thing', it can be overwhelming. 'It's not easy to play in another league, to play in a country different from yours,' he says. 'Even now I write in Spanish and translate it, and then I rewrite the translation.' And although he says the moment The Three Burials of Melquiades Estrada won a standing ovation at Cannes 'was one of the highest points in my professional life', there's a palpable restraint about him - something measured and contained that belies the intensity of his writing, which is unabashedly primal.

The 44-year-old author sees himself as part of a movement in Mexican culture, and doesn't distinguish between writing a screenplay and a novel. 'I consider myself a writer who chooses the best way to tell a story,' he says. 'Sometimes it's a screenplay, sometimes it's a short story, sometimes it's a novel. I consider the screenplay a literary genre, and I take care of the language, the structure, the dialogue and the character development as much as I would in a novel.'

There's a cinematic quality to The Night Buffalo. Born of his own youthful experiences in Mexico City (where Arriaga grew up and still lives), it's the story of Manuel, a young university student haunted by the suicide of his best friend and blood brother Gregorio, who insisted that the pair be tattooed with a picture of the night buffalo by the same needle so their blood would mingle.

Manuel is plagued by guilt brought on by his illicit relationship with Gregorio's girlfriend, Tania. Not that this prevents him from conducting secret affairs with Gregorio's sister and with a fellow student. When letters begin to arrive from the dead Gregorio, and Tania disappears, Manuel begins to unravel.

Part allegory, part chronicle of madness, The Night Buffalo plumbs the relationship between love and lust, violence and madness, with brutal frankness. Yet, like 21 Grams and A Sweet Scent of Death, it's an exploration of the impact the dead have on the living. 'That's a theme in all of my work from the very beginning,' says Arriaga. 'But it's much clearer in The Night Buffalo.'

Written in a fast-paced, fractured style familiar from his screenplays, the novel's genesis, as with all his work, is Mexico City. The rain-drenched city looms large in the tale, and mention of it is enough to provoke the softly spoken author into an impassioned discourse. 'Mexico City is one of the most powerful cities in the world. It has such a powerful culture and is such an intense city, you cannot go untouched by it.'

Many critics have been puzzled by the rainy, cosmopolitan world he portrays in the novel, he says. 'People expect Mexico City to be like Acapulco, with hot weather and palms. It's funny, because it is not far away from London or New York, but at the same time it has a difference - intensity - and it's that that's portrayed in The Night Buffalo.'

As he speaks of the great weight of the Mayan and Aztec civilisations on the 22 million inhabitants of modern Mexico City, and says the city 'had 600,000 inhabitants when London and Madrid had 8,000', Arriaga gives a sense of the passion and probing intelligence that underlie his writing and that drew him as a young man to first earn a master's degree in history. 'I have a passion for story and history has a lot of stories. I thought of history as a process of going deeper into storytelling.'

In many ways, Manuel's story in The Night Buffalo echoes his own, he says. The wayward son of a loving family, he became involved in gang wars in his neighbourhood of Unidad Modelo, in the Iztacalco precinct of Mexico City, eventually losing his sense of smell after being punched in a fight at the age of 13. But by the time he was 15, he had written, directed and produced 20 stage plays, and at 18 he was selling his short stories. 'I wrote for radio and television and then at 24 I began writing literature as a way of living.'

Ever since A Sweet Scent of Death was adapted into 'an awful movie that has nothing to do with my novel', he has made it his business to be closely involved with the filmmaking process, co-producing Amores Perros and 21 Grams. He's now working on a screen adaptation of The Night Buffalo. Arriaga says that almost all his work has been infused with a profound awareness of the consequences of violence. 'I don't make fun of violence. I went through very violent episodes when I was very young, and that makes you feel that violence is unnecessary.'

He loathes gratuitous violence, or films that portray death on a superficial level, which is why he placed a decaying corpse at the centre of The Three Burials of Melquiades Estrada. His finely layered, spare script about friendship and redemption, set in the desert border terrain between Texas and Mexico, revolves around a quixotic journey by a man determined to take his murdered friend's corpse to Mexico for burial - and to make the killer realise the enormity of his actions.

'A corpse is much more of a reminder of the way we're going to walk through death, and I wanted to get this idea across because in many films and often in the news, life and death have lost their real meaning. And for me, this is a film, a story, that reminds us how important each and every human life is.'

author's bookshelf

Light in August by William Faulkner

'For the beauty and the humanity.'

Dirty Havana Trilogy by Pedro Juan Gutierrez

'I like it for its eroticism, and its depth, and for the way it uses sex only as an excuse for deeper things.'

The Burning Plain by Juan Rulfo

'Again, because of the humanity and the emotion it brings.'

Flaubert's Parrot by Julian Barnes

'For the intelligence and the irony.'

Hamlet and Romeo and Juliet by William Shakespeare

'For the poetry of the language and the strong motivations of the characters. I love the way he forces characters into awkward relationships. The Shakespeare crystal is helpful for writers.'

WRITER'S NOTES

Genre Literary fiction, screenplays

Latest book The Night Buffalo

(Atria Books, $187)

Age 44

Born and lives Mexico City

Family Wife and two children

Next project A screen adaptation of The Night Buffalo and a new novel

Other screenplays Amores Perros (2000); Powder Keg (2001); 21 Grams (2003); Babel (2006), in post-production

Other novels Esquadron Guillotina (1991), A Sweet Scent of Death (1994)

What the papers say 'There is a melancholy poetry to Arriaga's prose that manages to survive even this brutal translation.' - Time Out on The Night Buffalo