In Blood Feud (Putnam, Nov.), sports columnist Lupica continues the story of Robert B. Parker’s female PI, Sunny Randall.

How did you come to write a Sunny Randall novel?

I was talking to my agent, Esther Newberg, last summer. I had just gone back and read the Randall novel Spare Change again, because I am always either rereading Bob’s books, or listening to the audiobooks. And I innocently asked why nobody had continued the Sunny books. She called Ivan Held, now my publisher, and Sara Minnich, now my editor, and called me back a few hours later. She said, “Would you mind writing a sample chapter?” I said, “Would I mind?” And told her she would have one in about a day. Which she did. It’s pretty much the first chapter of Blood Feud. And we were off. The minute I started writing, I realized once again what a powerful influence he’d been on me, especially when I was still writing mysteries.

Was writing someone else’s creation easier or harder than writing your own?

Once I started, I just knew how Bob Parker’s voice had been inside my head for a long time. And how much he’d influenced the three Peter Finley novels I’d written. From the time, page one, when Sunny says the UPS kid “ma’am-ed” her and her friend Spike asks if she shot him, I knew I was right where I belonged with these characters, with their voices, living in Bob’s world, playing in that league.

Does the fact that there were so few Randall novels give you more freedom to put your mark on the character, or make it more challenging to keep your Sunny faithful to Parker’s?

I love the idea that it’s been a decade since Bob’s last Sunny. That actually was pretty liberating. You could see Bob had been falling in love with this character and her possibilities. I can only imagine what six more Sunny books would have been like in his hands, in that amazing imagination.

How has your work writing about sports influenced your writing of fiction?

Writing a sports column taught me so much about story, and form, and structure. You’ve got to grab the reader’s attention. With a good sports column, you’ve got to use dialogue to tell your story; the story you’re writing in 800 or 900 or 1,000 words has to have a beginning, middle, and end. And here’s another way it helped me: I’m conditioned to writing in 800- or 900- or 1,000-word bursts. You write that much on a novel five days a week, and your story starts to take off. Bob Parker never wrote a sports column, but he had that kind of discipline, or he wouldn’t have been as prolific as he was.