Nancy Martin, author of the Blackbird Sisters mysteries, set among the Philadelphia social elite, introduces a working-class Pittsburgh sleuth, Roxy Abruzzo, in Our Lady of Immaculate Deception.

Will Roxy ever meet the Blackbird sisters?

Roxy is the kind of girl who'd crash her truck through the front door of those blue-blooded Blackbirds to steal their silver spoons—all for the right reasons, of course. Will their two worlds collide? Perhaps later. For the moment, I've got my hands full with all the shady characters in Roxy's blue-collar neighborhood—shifty mechanics, beauty shop divas, cheaters in the church bingo hall, trigger-happy demolition crews. I'm finding backstairs intrigue just as much fun as what happens at a charity ball.

Is there another Blackbird book in the works?

The Blackbird characters are simmering on my back burner, and I'll get back to them when their family pot boils over. I'm finishing up Roxy's second adventure and thinking ahead to the third.

How did Roxy evolve?

I spent a lot of time thinking about what forces can warp a young woman. I was listening to plenty of tough girl rock and roll—the playlist is on my Web site—and Roxy's voice started shouting back at me. She's loud and brave—don't call her plucky or she'll hit you with a tire iron!—but she has a bit of a broken soul.

Is it because Roxy's a single mom with a precocious teen daughter, Sage?

Roxy is difficult and complicated. Her daughter recognizes her flaws, and yes, maybe Sage is the adult in the relationship. But no teenage girl is an angel forever, so the tide will definitely turn.

Is your inner child wild like Roxy?

Sssh! My children think I'm a gracious lady, but I came of age in tumultuous times. I know my way around the concert parking lot. When we're idling in the car-pool lane at the preschool, who doesn't let her imagination wander? If your life's choices were different, could you have become a woman who's not quite domesticated, not always a “good girl”? Would you dare take the big risks, yet have a personal code? How far would you go to protect your friends and family? It's a delicious fantasy.

Would you call this a chickaboomboom thriller?

Can I steal that? I've been trying to come up with something. Comic noir? My books always start out very dark, with issues that I think are worth exploring. But the funny stuff bubbles up, little by little, until the story's tone ends up much different from where it started.