Marianna and I had been introduced a couple of years before by a mutual friend. We'd communicated by email, but had never met. She called me up one day and said, "I have an idea to make a film."

I get a lot of people calling me up and asking, "Can you make a film about this? Can you make a film about me?" Usually what I say, which is really true, is that I'm too busy and I'm so sorry. But when Marianna explained the idea for the film she imagined, I was very moved. Her goal was to raise awareness and get people to talk about Huntington's disease. When I realized how tough life is for people who have Huntington's in their family, I really felt like I wanted to help. It also seemed that having a camera around could give Marianna a sense of purpose -- the idea that her suffering might be help ease somebody else's suffering could be something to cling to.

We wanted to capture what changes when you learn what comes next. The thing that people forget to document is the beginning, and we had a chance to get the beginning. This is why Marianna and I figured out we would shoot the dinner scene with her friends.

It is a film about Marianna's friends absorbing the news as well, so that scene shows how other people are trying to get their heads around things. They also Google the disease; I think that's a typical response these days. It helped elucidate what the stakes are.

The disease is hard to imagine; it's very specific and hard to describe. That footage shows what the disease is and what's at stake. I think that the tone in Marianna's voice is very telling. But we didn't want to drag it out. I don't believe in agony for the sake of it. I always wanted to make sure that it was never gratuitous.

The whole thing is moving. The title of the film comes from the poem:

"And the lion's mouth opens and yer staring at his teeth
And his jaws start closin with you underneath"

That credibly pulls at the feeling of something that?s very scary.

The main thing is that we are trying to get the word out about Huntington's disease. It's a disease you want people to know about. And I hope they enjoy the movie and get to know Marianna. She is amazing. I feel real joy just to watch her in action.