In the shattered calm of the Mexican night, sitting atop a railroad tanker car, Cary Joji Fukunaga didn't know that a man was being murdered.
But he'd heard the screams, gunshots and shouts in Spanish of "Bandits!" and he was bracing to make a run for it.
It was summer of 2005, and Fukunaga was researching the screenplay for his first feature film, Sin Nombre, the harrowing but uplifting saga of a Honduran girl and a Mexican ex-gang banger trying to train-hop illegally into the United States.
Most aspiring auteurs probably would have drafted that story from home.
But Fukunaga (31), a Californian native who writes and directs movies as if he were practising an extreme sport, wanted to experience the hazards and terrors faced by thousands of economic refugees from south of the border every year.
So he set off for southern Mexico to ride the rails, braving foul weather, thugs and the danger of being swept under the trains' limb-severing wheels.
"It felt like being a hobo in the '30s," he says, hunching his slender, 180cm-plus frame behind a metal desk in the Manhattan offices of Focus Features.
In the process, Fukunaga, who grew up in northern California but has lived in New York for seven and a-half years, has crafted a significant new addition to the corpus of movies dealing with the Latin American immigrant experience, including Gregory Nava's El Norte (1983), Joshua Marston's Maria Full of Grace (2004) and Patricia Riggen's 2008 film La Misma Luna (Under the Same Moon).
At January's Sundance Film Festival, it won awards for directing and cinematography.
The movie's title refers to the anonymity of the millions of migrants, legal and illegal, who work in the United States.
But in Sin Nombre, personalities are attached to those desperate travellers: Sayra, a young native of Tegucigalpa, Honduras, hoping to unite with her father's "second family" in New York, and Willy, a Mexican outcast and former member of the vicious Mara Salvatrucha gang.
Yoked by fate, they make their way up Mexico's Gulf Coast and to the US.
During his research and filming in Mexico, Fukunaga met scores of such trekkers.
He also met a Honduran man who made about $US3 ($NZ5) a day in a country where milk costs $US1.
"Why is he going to the United States?" Fukunaga asks rhetorically.
"It's not because he thinks our streets are paved with gold; it's not because he thinks life's going to be roses and flowers and hearts in the United States. It's because that's where he can make $13 an hour ... and send most of it back" to his family.
Issues of immigration and identity cut deep in Fukunaga's own character.
"What is Cary?" is the question often put to Sin Nombre producer Amy Kaufman.
The facile answer is that he's a wandering spirit with a Japanese father, a Swedish mother, a Chicano stepfather and an Argentine stepmother.
Growing up, he shuffled from the suburbs to the country to the barrio to the east San Francisco Bay Area's hillside bourgeois enclaves.
Fukunaga made his first short films at New York University's Graduate Film Programme after earning a bachelor's degree in history at the University of California, Santa Cruz.
From a political perspective, he regards the US's decades-old immigration conundrum as a case of fairness and social justice.
"We are a country of immigrants, and I don't know why it is a tendency for humans to forget that fact," he says.
He describes the theme of Sin Nombre as "families in transition ... the coming apart and re-creation of families in different forms.
I grew up with families constantly in transition, different sort of iterations of it."
The movie's catalyst was Fukunaga's 2004 short film Victoria para chino, which screened at the 2005 Sundance Film Festival and has won many international awards.
The 13-minute movie dramatises a May 2003 incident in which illegal immigrants being smuggled into the US in a truck were overwhelmed by overcrowding and Texas heat, causing 19 deaths.
Fukunaga and Kaufman say they were moved by the Los Angeles Times 2002 Pulitzer Prize-winning series "Enrique's Journey", about a Honduran boy's train journey to the US in search of his mother.
Fukunaga also was inspired by Days of Heaven, Terrence Malick's epic of migrant farm hands in 1916 Texas.
The contemporary migrant experience is no less lacking in poetry or brutality.
Among the hard-luck cases are those who lack enough money to pay a coyote, or guide, to help them cross the border and must ride atop a railroad car.
Sin Nombre captures their plight through the accents, slang, social customs, sights, sounds, smells and music of Mexico and Central America with a precision and authenticity rarely found in US-made movies set in foreign climes.
Fukunaga also visited prisons to interview gang members involved in human trafficking, and shelters serving young men and boys who had lost arms and legs in train accidents.
Kaufman met former gang members and agencies that work with them in Los Angeles.
They shot on gang turf in Mexico, and a few gang members appear as extras.
"Cary took the challenge of making a movie in another language, about another culture, incredibly seriously," Kaufman says.
"For him that meant that he had to be incredibly authentic, and with people on the set from Honduras checking things that you would never even notice, like the different way that people eat tacos in Honduras and in Mexico."
In casting the film, the crucial decision was to pair Paulina Gaitan, a young but experienced Mexican actress, with Edgar Flores, a less-polished Honduran actor.
Kaufman had seen Gaitan in Marco Kreuzpaintner's Trade with Kevin Kline, and felt sure she'd deliver the performance that Fukunaga wanted.
Flores turned up at an open casting call in Tegucigalpa and won the part based on his striking looks and ability to play a tough, if vulnerable, gang banger.
"If you look at Edgar's eyes, he's not acting," Fukunaga says.
Catch it
Sin Nombre screens at Rialto on Friday, July 31 at 4.15pm and on Sunday, August 1 at 6.15pm.
