Kidman was in San Francisco to speak at the groundbreaking for a centre dedicated to stopping violence against women and children. ''Someone said to me, 'That's Phil Kaufman over there,''' she recalls. ''I could see the pain in his face, his grief. Because of my relationship with my husband,

I couldn't imagine what he was going through after so many years with her. I held his hand and said, 'How are you?' It was one of those meetings with nothing superficial, very immediate and deep.''

''She'd heard about Rose,'' Kaufman says. ''I just remember this long, silent look that we had, very penetrating.'' With others clamouring to speak with the star it was a short conversation, but Kidman managed to tell him, ''I'd love to work with you.''

Kaufman hadn't directed a movie since 2004 but he'd been working on lots of projects, one of them a script centred on the turbulent relationship of Ernest Hemingway and his third wife, the foreign correspondent Martha Gellhorn, who together and separately covered the Spanish Civil War, civil war in China, and Europe during World War II. During much of their time together they lived in Cuba.

''I didn't offer to show Nicole the script,'' Kaufman says. ''It was still sort of a hidden project. But two days later, she called: 'I've read the script and I want to do it. No matter how long it takes, I'm in.'''

It must have been a strange time for Kaufman and his producer son, Peter - losing Rose only a month earlier, living in the fog of grief and loss. Philip Kaufman could hardly focus on the script for Hemingway & Gellhorn, which he'd been revising with his friend Jerry Stahl. But HBO wanted the film, a good start had been made on the screenplay and he had his Gellhorn.

As Kaufman and Stahl started reworking the script, HBO asked for a short film illustrating how Hemingway & Gellhorn would incorporate newly filmed material with archival footage. In Kaufman's basement office, film editor Rob Bonz began compiling filmed segments plus archival scenes from earlier Kaufman movies. Chris Morley, a visual-effects genius, began working with advanced digital techniques to ''nest'' the modern-day actors in the archival footage in ways far superior to those of the past.

Meanwhile, Kaufman and Stahl ramped up the film's romantic element and expanded the settings. ''We took a sharp turn and created what amounted to a completely different script,'' Kaufman says.

At that point, Kaufman sent the script to a close friend, entertainment lawyer Barry Hirsch, ''just to see what he thought''. Hirsch, whose clients include Francis Ford Coppola, Sean Penn and Clive Owen, told Kaufman: ''I think this is something Clive would like.''

''So I got a call from Clive Owen in London,'' Kaufman recalls, ''and he says, 'I just read the script and it's a stormin' script' - he used the word stormin'. Just like Nicole, he wanted in. Now we had to work out the scheduling.''

''It looked a bit like it wasn't gonna happen,'' Owen says, ''because I was committed to another film. It looked like I would miss a great opportunity … Then Phil called and said, 'If we waited, would you give me your word you won't mess me about?'''

Filming began less than a year later, in February 2011. Kaufman lined up several actors he'd worked with in the past, such as David Strathairn, Robert Duvall and Brooke Adams.

To play Joris Ivens, the Dutch filmmaker Hemingway and Gellhorn helped as he shot footage for his famed documentary on the fight against fascism in Spain, Kaufman chose Lars Ulrich of Metallica, who had done a reading with Kaufman years earlier.

''He called out of the blue and offered me the part on the phone,'' Ulrich says. At the time, Kaufman, who loves stumbling on ''the truth in unexpected places,'' was unaware Metallica's second album had a song called For Whom the Bell Tolls, loosely inspired by ''Hemingway's shenanigans'' in the Spanish Civil War, Ulrich says.

The actors all speak of how collaborative the filmmaking was. ''Instead of dictating what he wanted, Phil was always encouraging you to be part of the process,'' Ulrich says.

''I'd jump at the chance to work with him again,'' Kidman says. ''We had many conversations where I opened up, and he opened up. I feel protected and safe with him, which is why I'd do anything for him now.''

As with his other historical films, Kaufman felt the need to be utterly accurate. He was delighted when his costume designer found clothes dating back to the '30s in a Spanish costume house.

''As we're coming to know, the old Hollywood period films just sucked because everybody was in brand-new clothes,'' Kaufman says. ''It was as if people in the past went to the cleaners every week … Our little crew was hungry for authenticity. But anything in the past, little things, can lead you into the present.''

People close to Kaufman have no doubt that the relationship of his protagonists means a great deal to him personally. Some feel Hemingway & Gellhorn may even be a tribute to his relationship with his late wife Rose.

''You bring your experience into whatever you do,'' his son Peter says circumspectly. ''Rose had this Martha Gellhorn-esque spirit of not caring about what convention tells you to do but doing what's in your heart, fighting for the underdog … doing things for the right reasons, and living a creative life.''

San Francisco Chronicle

Nicole Kidman hasn't worked in

TV since the 1989 mini-series, Bangkok Hilton. It took a project like Hemingway & Gellhorn to get her back to the small screen. She talks to Rick Bentley about playing Martha Gellhorn, one of the most significant war correspondents of the 20th century.

How different is it to play a role based on a real person?

It's like doing the homework before the exam. You want to have the well of information. And then it's trying to find her essence. Not to be a caricature, but to find what was her essence, what was the beating heart of her, and try to be true to that rather than the physical; rather than the mannerisms.

What was Hemingway's effect on Gellhorn?

I think Martha found her voice when she was with Hemingway. And he was a big part of helping her to, as he says [in] a line in the film … ''get in the ring and start throwing some punches for what you believe in''. The great thing about Gellhorn was that she was the first female war correspondent and she wrote about people's lives, and she wrote with such direct truth. That's hard to do.

How was she different from Hemingway?

She's not Hemingway. She didn't want to write novels. She wants to be a correspondent. You see, in the film, her on the frontline. You see her hands bloody. She's a sponge, and then she's able to sort of feed that back to America and the world.

Why didn't their marriage last longer?

They couldn't be together because she wouldn't comply. He thought he wanted a woman who was an adventurer and then when he finally gets her and she won't settle down, and she won't be domesticated, he doesn't know what to do with that.

How difficult is it to film a love scene with a building falling down around you?

It's awesome. Phil [Kaufman, the director] was like, ''OK. We're going to have - we want stuff coming down.'' And I think … it really emphasises that they came together through war. They fed off that drama and that energy, in a way. Two people that would make love through a building collapsing, that says something about who they are. And that's why I think that was important, that scene, because you really see that this is where they are their most comfortable, their most passionate, and that's where their love thrives.

MCT Information Services

Hemingway & Gelhorn
Showcase, Wednesday, 8.40pm