Detective Merci Rayborn is really maturing isn't she? When she debuted in The Blue Hour I wasn"t sure whether I liked her or not, as she had such an aggressive chip on her shoulder. Now she's become an empathetic yet still tough-as-nails mother. What's happened to her?

Well, I hope she's growing up. The idea in The Blue Hour is that Merci is so young and naive and arrogant that she thinks her will can't be denied. She learns otherwise in rather dramatic fashion, which is one of the reasons I decided to write about her again. In the next book, Red Light, Merci's confidence is shot -- as a result of what happened in the previous story. So the questions became, 'Can a crushed spirit lead to bad judgment? Can she use her instincts and training to do a good job?' In Black Water, she's beyond the illusion of invincibility but she isn't crushed, either. Black Water is, in many ways, about her coming back to life.

You begin Black Water with the events of the evening of Gwen Wildcraft's murder, told from Archie's perspective. This makes it pretty clear that Archie wasn't the killer. Did you plan from the start to do this, or did you ever think about putting doubt into the reader's mind about his potential guilt?

I wanted the reader to know the score up front. I thought it would form a nice, intimate pact between writer and reader and Archie. We're the only ones who know the truth, though Archie himself begins to doubt it. It lets us side with him more wholeheartedly.

Archie has a pretty bad head injury after the incident which kills his wife. I found myself wondering whether his later actions were those of a man influenced by a head injury, or that of a heart-broken man. Did you intend to leave it ambiguous?

Yes. I think the answer is, both. That was one of the reasons I had Archie's amygdala damaged. In the human brain, the amygdala allows the person to attach emotion to memory. So, if a bullet ruins your amygdala -- as it does Archie's - you can live and act and think, but you can't put appropriate emotions to those things. Thus, the bullet in Archie's brain ruins his heart, too.

The relationship Merci has with her child, Tim, is moving and well written. You read like a writer who's really experienced the joys and responsibilities of bringing up children. Am I right?

Yes, I have. I lifted a lot of Tim, Jr.'s dialogue from my own sons. I've had complaints from readers that there's too much kid stuff in the Merci books but I kind of enjoy it. I never quite know if I'm translating the emotions of fatherhood to the page, or just doing some kind of psychological homage to my own progeny. It seems, though, that if you're going to write a full character and that character has a young child, then she's going to spend a lot of time thinking about that child and loving it and taking care of it. How can you ignore that part of the character? I don't want to.

Merci seems to find herself drawn romantically to quite a few men, yet still holds onto the memory of Hess, the father of her child. Do you think Merci could ever settle down with one man for the long haul, or is she a woman destined for single motherhood and the freedom it brings?

I see her as hungry and perhaps insatiable. Or maybe I just want to see her that way because I think she's a more interesting character when she's not happy. She's coupled at the end of Black Water, so I'll have to see what's going to happen. Strife makes good drama, and contentment doesn't.

Archie and his wife, Gwen, seem so intensely in love. The intensity of this love was fascinating and moving to read. How common do you think this depth of love is between couples?

You know, I see it in some people and it seems completely lacking in others. To me, Archie and Gwen are exceptionally deep in their love for each other. Their love is almost unbelievable -- which is why you don't trust it. Where's the betrayal? Where's the contempt? Where's the complacency or the weakness for temptation? I like the idea that a love can be deep and simple and pretty much bulletproof. But, I'm a mystery writer so here comes the bullet. Literally.

Black Water is the third in the series (Blue Hour, Red Light...) featuring Merci Rayborn, but you've also got a paperback novel, Silent Joe, coming out this month, which is a stand alone novel. Is writing a stand alone a different experience for you, and do you have any preference?

The series books are easier in some ways, because you have so many questions answered ahead of time -- main character, setting, basic tone and type of story. The hard part is keeping these things fresh and strong. Part of being a writer is going where you've never been before, coming back with the goods. It makes your heartbeat and your blood rush. You can over-regulate the risk factor in a series, then it turns bland. I write all my books as stand alones, whether they really are or not. Shaping a story simply for the purpose of leaving the reader hanging for the next one is not a goal I respect.

You've been compared with a few other thriller writers, including Michael Connolly and Thomas Harris, but whom would you like to be compared with?

Them, for sure. I also admire writers like John Le Carre and Elmore Leonard, with whom I have not very much in common as a writer. When all is said and done I'd like to be incomparable, wouldn't you?

The ideas in your books are pretty ingenious. Where do you get them from? Does plot come first and then characters, or the other way round?

You know, it's funny how plot and character kind of evolve together. Truly, the characters come first, and I try to figure some precarious state of affairs for them to begin the novel in. The story becomes a matter of what they're going to do with the challenge. And, of course, the problem changes as the characters apply their personalities to it. So far as ideas go, I've never thought of myself as particularly clever. I think a lot of what might seem ingenious - and fun to read - comes from the author getting himself out of a jam.

You seem to have a strong fascination with police work. Did you ever think about joining the police? You seem to understand your officers so well.

I've never considered joining a police department. Too cowardly, too stubborn to work well in a bureaucracy. I respect law enforcement officers, for sure. I know a few. What I like most about the police world is the tribalism -- the 'them and us' mentality. What you have is this tiny group of armed men and women who've taken on the job as enforcers of the law. Then you get into Plato's questions about who polices the police, and suddenly you're in this very complex moral world. I like the idea of sacrifice, too. Law enforcers make certain sacrifices. So do accountants, athletes, writers and homemakers - though different. So you vet the quality of the person against the circumstances they operate in and you come up with character. You come up with what a hero is, which is an interesting question.