LOS ANGELES - Jodie Foster does not step in front of the camera too often these days.
The actress - who won the Best Actress Oscar twice, for the rape drama The Accused (1988) and psychological thriller The Silence Of The Lambs (1991) - has in the last decade leaned more towards directing, with films such as hostage drama Money Monster (2016).
But she made an exception for the legal drama The Mauritanian, which opens in Singapore on April 8.
Co-starring Tahar Rahim, Shailene Woodley and Benedict Cumberbatch, it tells the story of Mohamedou Ould Slahi, a Mauritanian man held for 14 years without charge at the American detention camp in Guantanamo Bay, Cuba, where he was relentlessly abused and tortured.
As bleak as that sounds, the film, which is based on Slahi's 2015 memoir, is surprisingly uplifting - and this was one reason Foster felt she could not pass on the role.
"It was a story that needed to be told," says the 58-year-old.
"It was a really amazing screenplay about the story of Mohamedou Ould Slahi, who was abducted from his home country and kept without charge for 14 years.
"Finally, they managed to secure his release and it was Nancy Hollander, his lawyer, who helped with that process. But it's an amazing story of courage and humanity in the face of terror and fear."
Foster wanted to shine a light on a particularly dark period of United States history as well, she says.
"It is the story of us as Americans: what we did after the (Sept 11, 2001 terrorist attacks) and how we reacted to those terrible events."
Rahim, who plays Slahi, felt similarly compelled.
"When I started reading the script, I felt like I was seeing the movie and that it was really important to tell that story, even though this beautiful part was very hard to portray," says the 39-year-old French actor, who starred in the prison drama A Prophet (2009).
Hollander is the first real, living person Foster has played - which presented its own challenges.
"There are constraints incarnating a real person," she says. "I just wanted to make sure it wasn't an imitation and that's what I said to Nancy - that we wanted to serve Mohamedou's story and there might be some changes to what really happened."
Her portrayal is also "a lot meaner than the real Nancy is and certainly a lot ruder", Foster says. "But I think she's okay with it."
For Rahim, it was useful meeting the real Slahi, who was released from Guantanamo Bay in 2016 and is now 50 years old.
"It can be scary when you meet a real person that you have to play and you realise, 'I might not be able to do this.'
"But in the case of Mohamedou, it helped me to understand many things. Usually as an actor, you have a couple of questions, but when I met him, I had to throw them all away and just listen to the man, try to understand him and try to capture his spirit.
"Plus, it was a pleasure to meet someone that extraordinary."
The movie, which captures Slahi's upbeat personality and attitude, got his stamp of approval when he saw it, Rahim reports.
"I called him and he said he was really happy about how it told his story. But he said it's not just his movie, it's also the movie of the (other) people who have been through this."
The film honours the spirit of what Slahi went through, says Foster.
"It's hard to describe what an incredible person he is - that he was able to take these horrifying circumstances and emerge as somebody who was a better human being than when he went in.
"This, in a way, was a spiritual experience."
She adds: "Yes, there is an amount of damage because of the torture he went through, psychologically and physically. But he didn't let it break him.
"Instead, he became more faithful, more vulnerable, more open, more kind - and more funny, if that's possible. It's a real testament and he's somebody that we can really learn from."
The Mauritanian opens on April 8.