The most surprising thing to me is what an incredibly intense effort it's been to create a world from the ground up. I had run a show that had already existed and had been created by the show-runner, Meredith [Stiehm]. It's a very different experience to come in at ground zero and meet people and assemble the cast and crew. As a group and as a family, we're creating this world.

Creating a world that reflects the inner voyage of our characters was really important. Also, because this isn't a black and white show, and this isn't about bad guys and good guys, but it's about good men being capable of bad things and vice versa, I wanted to be in a city that had contradiction.

Before I write anything, before I create any assumption in my mind about what it's like to be in that world, I go out there first. I'm very drawn to darkness and light, very drawn to cop drama, because there are very few places besides war and murder and a homicide investigation where you see the extremes of human nature - the darkest crevices and cracks in what people do to one another.

I've always been kind of drawn to the extremities of human nature. I wrote my first screenplay when I was 16. The initial idea was a friendship between two prostitutes, and I spent time with a vice squad guy in Cincinnati who brought me to a brothel and gave me the rundown on how street prostitution works.

I am endlessly fascinated by this notion that everyone has a secret. Some of our secrets are tiny, small things, and some of them are huge. Given that reality of the human condition, that's what our characters will go through. There will be some things where you'll just be like, "What the hell! How the hell did that happen?"

It's the open ocean right now because it's so unique. It's a really unique way of doing American television. There are a million possibilities. We can stay with the cops. We can introduce new worlds. And, who knows where it will end.

But, for the role of Sarah Linden, we saw everybody. Everybody wanted this role. Every female actor in town really wanted to play a real woman and be in this drama. It was incredible that all these women were coming in. And then, Mireille [Enos] walked in the door and she was reading the lines that I had written, and I saw her in that field. I was like, "Wow, she's the one."