In the romantic thriller Liar, Liar (Kensington, July), a woman investigates the death of someone who resembles her long-missing mother.

Liar, Liar centers around the disappearance of Marilyn Monroe impersonator Didi Storm. Where did the character come from?

I’m a small-town girl. I live in suburbia, and I grew up in rural America, and I wanted to do something that had cities. I had this picture of this woman in a blond wig and makeup in the desert with a scarf around her neck offering up her babies for sale to their father. I had that scene in my mind for years but nothing came of it. Finally I thought, “I have to get this out of my head.” But I didn’t want it to be outdated or historical. I mean, Marilyn Monroe has been dead, what, 50 years? So I wanted it to be an impersonator. And it just all came together from there.

Liar, Liar is driven by a complicated mother-daughter relationship. What led you to focus on this dynamic?

Well, first of all, I needed a heroine. I wanted somebody who was kind of good but would bend the rules. So it was going to be Didi’s daughter. And there was no way Didi Storm was going to have a normal mother-daughter relationship! I wanted this girl to want to have her own life but be trapped by her mother and her situation, especially with the babies and feeling obligated to be more of a mother to them than her mother was to her.

I do believe that the growing-up years of your life, the very young years, are so, so important to your development. And the relationships that you form then help develop the relationships you have later in life. So I think that if you have traumatic or difficult childhood experiences, it might make you more of an interesting character to write about. I also do a lot of religion in my books because I think your religious upbringing is very indicative of who you’re going to be in your later life—if you’re going to reject it or if you’re going to embrace it.

Speaking of religion, one of the villains, an unnamed assassin who hunts the main characters, has a strange obsession with the hymn “This Little Light of Mine.” Why this song?

Well, it’s a song from my youth, kind of a little, lilting song. And I thought it made a nice little counterbalance and juxtaposition to what he was actually doing. He needed something from his own youth to settle his nerves and to make him feel important—just kind of a little quirk. I remember the song from going to church camp. So you know, sometimes things from my past are really useful. I’m now 67, so to be relevant today I have to go beyond even my children’s age. There’s a big gap between my children and grandchildren, of course, and that’s where I have to tap in, because those are the young readers. I’m trying not to be old and creaky. And it’s really hard, let me tell you!