What goes into writing a good mystery? While it’s critical to have a compelling plot filled with twists and turns, I’ve always believed that the book’s heroine – and the development of her “real life” – was at least as important. When I started writing the Reigning Cats & Dogs mystery series, I wanted the focus to be my protagonist, Jessica Popper. Jessie is a veterinarian with a mobile services unit, essentially a clinic on wheels. I chose to make her practice mobile instead of based in a regular office because she needed an excuse to go out into the community every day, talking to suspects and ferreting out clues. But since I love to incorporate humor in all my books, I wanted her to be sassy, independent, and strong-headed, as well as someone who was battling a few demons. The main one is her conflict over commitment, which provides the ups and downs she experiences with her boyfriend Nick. (I tried to model their relationship after the sparkling repartee in those wonderful old Katherine Hepburn-Spencer Tracy flicks – or one of my favorite movies of all times, It Happened One Night.) The Reigning Cats & Dogs series was already…