A London hotel a month before the worldwide roll-out of Quantum Of Solace, the 22nd James Bond movie, from October 31, and Marc Forster is looking exhausted. He signed on to direct the film in the summer of 2007 - in other words, he had a little over a year in which to make a Bond movie with all the bells and whistles.

Ask him how easily he fitted into the Bond "family" and Forster replies he was initially reluctant to make the movie. "One of the things was that I had to bring my own 'family' with me. I brought all my collaborators."

Cinematographer Roberto Schaefer and editor Matt Cheese were among those who had worked with Forster before. "It was important to me that I could make the movie my own and create a movie that has a specific look and has a connection to my previous work," he says.

"The reason I accepted the movie was that I felt Bond as a character is emotionally repressed, which I find interesting and has a link to my other work. I felt it would be an interesting experiment, almost like a film-maker who works in a political regime with extremely strong censorship - within that regime, you can still make a film which very subtly brings in what is essential."

When Forster boarded the project, there was a screenplay by Neal Purvis and Robert Wade which had been developed with producers Barbara Broccoli and Michael G Wilson of Eon Productions. Then Paul Haggis, who worked on the previous Bond movie, Casino Royale, was brought in.

"Paul gave us a draft and a polish of the script, but as he was heavily involved promoting his own movie (In The Valley Of Elah), I realised early on that it would be impossible for him to hand in a completed draft before the beginning of the writers' strike. For that reason, Daniel (Craig) and I started early on to work on the character's journey ourselves," the director says.

Production on MGM/Sony's Quantum Of Solace began in January 2008 (although second unit filming had started in the summer of 2007). Forster knew he was locked into a late autumn release date.

"It was very intense," the director says. "It wasn't so much that the release date was set and that I had very little time in post-production. The main thing was there was no script in place when we started. That was the key issue. There was not really a story that I felt 100% confident and good about. When there was the writers' strike, I knew that by April, we would run out of story. In February, I brought in another writer, Josh Zetumer, to do a few polishes, rewrites and ideas between Danny, me and him."

The other challenge, the director adds, was that Casino Royale had been so successful. "So many people loved the movie. To live up to that in Quantum Of Solace and to be up to par with that is another added pressure."

Quantum Of Solace is certainly one of the few Bond movies with an environmental undertow. The villain, played by Mathieu Amalric, is chairman of an organisation called Green Planet. "I said to Paul Haggis that I wanted him to be an environmentalist and have this environmentalist way of trying to protect the world. To be green is so fashionable now. Even Chevron and Shell and all these big companies and corporations suddenly use it for their advantage and say, 'Look how green we are.' But ultimately they use it to enrich themselves."

Bond villains, Forster reflects, have shifted. In a post-Cold War era, the lines between good and bad are increasingly blurred. However, both he and Craig agreed about how Bond should be portrayed. "The character has this hard shell outside but still ultimately has this vulnerability. There is this isolation and this pain."

The film-makers wanted to "go deeper into that pain and have that pain reflected on screen".

"But one of the successes of Bond is his mystery," says Forster. "You don't want to have Bond explain himself emotionally or analyse (himself) too much. So I created Camille (played by Olga Kurylenko) as one of the Bond girls, who is a mirror image of him. She's an assassin and has a revenge motive."

By putting words into her mouth, Forster hoped to hint at Bond's feelings too. He adds that in all his films, the lead characters have been emotionally repressed, "very similar to Bond. That's how I could connect to him. I'm coming from a culture that is emotionally closed (Forster, who has a German-Swiss background, was brought up in the Swiss town of Davos). That's why I always relate to that kind of character. Bond has that too at his core."

Forster's admission that he "treated the film early on as an art film" will startle 007 fans who expect their Bond movies to revolve around women, Martinis and fast cars. Forster, though, is known as an auteur. After making films such as Monster's Ball, Finding Neverland and The Kite Runner, how did he feel about dealing with the product placement and commercial pressures that come hand in hand with 007 on screen'

"That was at the beginning a little tricky, but what I said was I was not willing to shoot a shot that was featuring a product just for the purpose of featuring the product unless it happens to be part of the story. I feel this has been overdone in the past and it takes you out of the movie."

Yes, Forster admits, he is tired after working so ferociously to finish Quantum Of Solace. "But the good thing is I feel very positive because I love the movie. I feel the movie really works."

Ask him if Bond 23 is in his sights and he gives what appears to be an equivocal answer. "No, it's something Barbara and Michael asked me about but I'm not really interested ... but never say never!"