By Darren Waters
BBC News entertainment reporter in Cannes
US director Richard Linklater is a Cannes rarity - a film-maker with two movies showing in different sections of the festival.
Towards the end of Fast Food Nation, his entry in the main competition, two characters walk through the killing floor of a giant meat-packing factory, surrounded on all sides by mechanised slaughter and cattle carcasses.
Ten films in, Linklater says he feels his career is "just starting"
It is a disturbing and emotive climax to his film; a scene which Linklater describes as the hardest filming of his life.
"It was a lot like being a soldier and seeing your buddies on either side of you being shot," he tells the BBC News website. "You can't feel at that moment."
Sat in the Grand Salon in Cannes' Carlton Hotel, he has the crumpled look of someone with jet lag who only received his wake-up call 30 minutes earlier.
But he also seems remarkably at ease for a man in Cannes for the first time and facing a gruelling day of interviews.
And he is clearly enjoying having two movies - A Scanner Darkly is in the Un Certain Regard section - to show off: "I am making up for lost time."
Fast Food Nation is based on the best-selling non-fiction book by Eric Schlosser, who co-wrote the screenplay with Linklater.
It intertwines three fictional stories: Mexican illegal immigrants entering the US to work at a meat-processing plant; a fast food executive's investigation into the discovery of cattle faeces in burgers; and a high school student and burger bar worker who takes her first steps as an activist.
Linklater says: "It started with characters. The issues grew out of the situations, how these people were living and what was going on in their lives.
"I wanted to explore these people's lives - I didn't want them to be representatives of an issue.
"I wanted them to be a person first, someone who is living in a world of issues they are barely aware of. That's what happens in the real world."
The film-maker had been sceptical when he first met Schlosser about the possibility of a film version of Fast Food Nation.
"I thought it would be a really quick meeting because I do not make documentaries."
But Schlosser pitched the movie as a dramatic story, not a documentary, sparking the director's interest.
Keanu Reeves stars in A Scanner Darkly, which is part animation
"The focus was on all sides of the fast food industry. I'd always wanted to make a film about industrial workers."
He adds: "I am all for anything that peels back what is in front of you and shows you the reality of how you got to this point - whether that is the clothes you are wearing, the food you are eating, the car you are driving, what's going on in your own government or what's behind a war."
In the movie there is a scene in which cattle freed from their pens by student activists merely stand around rather than making a bid for freedom.
Was this a metaphor for the audience who do nothing despite being told the truth behind a part of their lives?
"In this culture we cast our ballots with our dollars so you have got to have an informed opinion," says Linklater.
"If you are wearing clothes you are wearing products that were made with slave labour. Whether it's chocolate, diamonds or clothing, you should know that.
"When you know that you can make a choice."
He looks slightly put out when I imply that he and Donnie Darko director Richard Kelly are the youth of the main competition alongside veterans such as Ken Loach and Nanni Moretti.
"I am not the kid any more. I've made 10 movies now," he points out.
"Only yesterday I would have been the new guy. But I guess I'm enjoying my mid-career although I feel as though I'm only just starting."
He does add that he thought, "Wow," when he saw his name alongside that of Loach in the Cannes programme.
Ethan Hawke is among Fast Food Nation's impressive cast
Forty-three years old, he looks 10 years younger and will always be associated with a certain generation thanks to Slacker, his 1991 film about teen misfits in Austin, Texas.
Schlosser describes Linklater as the "real deal... completely without ego which is so rare in Hollywood".
As I pack up to leave Linklater is sat with another journalist, saying earnestly and believably: "It never started with the issues. It was always about the characters..."
It will be interesting to see what kind of audience the film will attract, especially in the US.