Me and Kirby are very collaborative and it changes from film to film. The first project we worked on together, Derrida, we co-directed. The last film Outrage, I was the producer and he was the director. This film was much more of a collaboration - he is the director and I am the producer - but this is a film by both of us.

Be very focused. Do your homework so your research and claims are unassailable. Make sure it is bulletproof and then make sure you are really focused. The thing I find is that the issues are usually so large that you try to cover a lot of ground. That's a natural impulse.

[Working with survivors] it's just a whole different level of concern and that is something that was categorically different working on this film than any other project we had done.

Me and Kirby are very collaborative and it changes from film to film. The first project we worked on together, Derrida, we co-directed. The last film Outrage, I was the producer and he was the director. This film was much more of a collaboration - he is the director and I am the producer - but this is a film by both of us.

Make sure it is not too diverse or spread out so people don't know where to go or what to do. So keep a sharp focus. It can be ambitious but should have a small agenda.

You always try and make a film that is a letter that will be read and we are so glad that it is being read by the right people in the right place and is inspiring change. It is also gratifying that the survivors are finding it healing and transformative. That's been really great.

The difficulty is the levels of secrecy we had to maintain around the project at all different times. We had to keep it a secret while making it so we could move under the radar so we could get the stories. Before it came out we had to keep it on lock down to protect the safety and security of some people who appear in the film.