The Sessions Helen Hunt

It's also intriguing that Cheryl didn't ask for her name to be changed, an openness that's reflected in the film, in which her husband (Adam Arkin) is fully aware and accepting of her profession. Lewin says he had her blessing to be as open as possible, bar a few notes. "Cheryl, for all that she's had a lot of experience in life, is still a very innocent, trusting individual. And I tried to reciprocate that by keeping her involved, and before I sent anyone else the script, I sent to her, and to Susan. And she gave me quite detailed notes, some of them were very amusing. Certain ways she wanted to be depicted. She didn't want to be depicted as smoking, she never smoked. She didn't want to be depicted as using harsh language with her son... One of the paradoxes of Cheryl's character was that on one hand, she was a typical, middle class American family values soccer mom, with a garden, and a mortgage and a teenage kid and all of that, and at the same time, doing this very unusual thing. So I felt I needed to show her family situation, so that we understood. She didn't share an apartment with two other girls one of whom was a junkie, or whatever. That part of the story was that she was a very conscientious parent."

Of course, Cheryl, and Helen Hunt's performance, is only one half of the film, with the Oscar-tipped John Hawkes, giving a phenomenal turn as O'Brien. Interestingly, Lewin actually wasn't aware of the actor until he started to cast the film. "I've got to give credit to our casting director," he said. "I really wasn't aware of him, and she made me aware of him, and she was so passionate about him that I took her seriously. So I did my homework, and watched everything of his that I could get my hands on, and when we met, we spent quite a lot of time together, arriving at a common view of what the film was to be like. At the end of which, I felt he was a gift."

The Sessions John Hawkes

Although the film premiered in January at Sundance, Lewin's remained busy, both with readying the movie for release ("If you sell it, as we did, you have to go through all the elements of delivery, which are endless," he told us, adding "I don't think people appreciate that"), and on the press tour, which is likely to last through to early next year. But he's starting to think about what could come next, saying " I've been getting a lot of scripts, and I'm kicking the tyres on a bunch of different projects."

One such potential is "Bridge Of Sighs," a thriller about a Death Row inmate. Lewin says that it's "a lot darker... I look at it and say 'who wrote this?' I know I wrote it myself, but I'm not sure why or how." It's not necessarily next though. "It needs another pass," he told us, "and I'm just waiting for a little bit of headspace, because I'm a very inefficient writer. I'm also way behind on another writing assignment for Fox. It's based on a book, but I'm not sure I'm allowed to talk about it. It depends what plans they have for it. I certainly haven't committed to anything in particular, this is way too absorbing." If "The Sessions" is anything to go by, though, we'll be looking forward to whatever he picks out.

"The Sessions" is on limited release now.