OFTEN, a film director is nothing more than a hired hand roped in by a studio to fulfil a brief. At the other end of the spectrum, some film-makers are so intricately and passionately linked to their films that it appears as if they are nurturing a new member of their own family. Walter Salles, the Brazilian director of The Motorcycle Diaries (see review), falls firmly into this second category. His intelligence and enthusiasm have, in recent years, transformed him from a local film-maker into a charismatic ambassador for Latin American cinema across the globe. As well as directing his own films, he produces films by other Brazilian directors, including last year’s City of God.

The Motorcycle Diaries is a road movie that details the journey taken across South America in 1952 by a 23-year-old Ché Guevara (Gael García Bernal) and his 29-year-old travelling companion Alberto Granado (Rodrigo de la Serna). Salles first unveiled his film to great acclaim in January at the Sundance Film Festival and then presented it again five months later in Cannes (where, surprisingly, it won no prizes). Only last week, Salles was at the Edinburgh Film Festival, talking energetically to a public audience for over 90 minutes before leaping on a plane to London to do the same thing again at the National Film Theatre.

Salles’s captivating charm surely stems from the dedication and compassion that he applies to his film-making. To research The Motorcycle Diaries, this 48-year-old former documentary-maker and director of Central Station and Behind the Sun took to the roads of South America along with his Puerto Rican screenwriter, José Rivera. Together, they retraced the same motorbike trip that Guevara and Granado undertook when they were idealistic and reckless medical students from Buenos Aires.

Salles and Rivera travelled through Argentina, Chile and Peru seeking locations and gaining a sense of the journey taken by his characters exactly half a century before. “And we went to meet the Guevara family,” Salles explains, “who helped us a lot and gave us a wealth of information. And we met Alberto Granado himself, who is 83 years young, and living in Havana.”

Later on, Salles encouraged his actors to embrace the project with similar determination. The pair obliged, embarking on an intense period of reading. Bernal taught himself the nuances of Argentinian Spanish, and the pair enrolled in university classes to gain a better knowledge of South American history and culture.

“I prepared for four months,” Gael explains. “I researched Ché, the countries — Chile, Argentina, Peru — and the politics. We went to Cuba, Mexico and Argentina. We rode a motorcycle three times a week. We had seminars with leper doctors.”

Towards the end of The Motorcycle Diaries, we watch as Ché and Alberto spend a crucial fortnight living and working in the San Peblo leper colony in Peru. It’s here that we see the first real stirrings of Guevara as a political animal as he injects talk of a “united America” into a casual speech at his own birthday party. Salles filmed these scenes at the same colony that Guevara and Granado visited 50 years earlier and some older patients even remembered the pair’s original visit.

Gael laughs at this. “Ché has more friends and relatives than anyone in the world,” he says. “That’s something we found out very quickly!”

The scenes at the leper colony, involving its real patients and staff, are some of the film’s most moving. They say a lot about Salles’s approach to films — an approach rooted in documentaries. When he was casting Central Station, he was looking for a young boy to play a Rio street kid. Passing through an airport, he encountered a shoeshine boy who asked him for a small loan instead of begging. He was so impressed by the child’s integrity that he cast him and will soon use him again in his next film.

Indeed, throughout The Motorcycle Diaries, Salles improvises and incorporates the lives of real people and places.

“If you do a road movie based entirely on the screenplay, you are committing filmic suicide,” Salles says. “Sometimes, what is interesting doesn’t happen on the road, but on the margins of the road. If you refuse to look at the margins, the film will become very stilted.”

He goes on to explain how the problems of South America today — inequality, poverty, unemployment — are not so different from the problems of the 1950s. He wanted to stress this by making the film feel fresh and by avoiding the stilted feel of many historical dramas. Guevara’s wrangle with ideas of a united Latin American identity is a struggle that Salles feels acutely.

“I think this movie is a vision of ourselves and goes to our deepest roots,” de la Serna explains. “Especially in Argentina, where we’ve always had a Eurocentric vision that produces schizophrenia in our people. And it’s a part of our culture that has been forgotten — this search for an identity. I’m very proud I acted in this film, which is a trip to the inside of our continent and ourselves.”

Salles points out that Bernal is Mexican, de la Serna is Argentinian, Rivera is Puerto Rican, and Robert Redford, the producer who first instigated the project, is from the US. The Motorcycle Diaries inherently reflects the ideals at the core of the film and at the heart of Guevara’s thinking.

“Absolutely,” Salles agrees. “We discovered, just like Ernesto and Alberto discovered, that we were all pretty much part of the same continent. It gave us a certain serenity to discover where we are truly from.”

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