Stevens’s thriller Liars’ Paradox (Kensington, Jan.) features twins Jonathan and Julia Smith, whose paranoid mother raised them as spies.

What inspired Liars’ Paradox?

We see so much family drama in mainstream and literary fiction—you know, someone goes home to a family they haven’t seen in 20 years and slowly unravels this deep family dysfunction—but we never see it in thrillers. If you see it in a thriller, it’s as a plot device. We don’t actually have time for family drama in thrillers, because the thriller is all about explosions and whatever is pushing the plot. But what would happen if you took the same family dysfunction that you see in mainstream fiction—or even in real life, because there’s a lot of it in real life—and you layered that on top of a family of assassins, where everybody was capable of killing each other, and quite often wanted to?

Why choose fraternal twins as your series protagonists?

Twins are closer than most siblings. Twins also are the same age, which makes it a little easier to keep a timeline straight. And normally, twins are not competitive with each other—they are bonded. I felt that to take what is a natural bond and turn it on its head would add to the whole premise of family drama. We’re already going to the extreme with it—what’s one more notch we can take it?

Spy thrillers are stereotypically testosterone-fueled, but of the twins, Julia best fits the action-hero profile. Why?

Simply because I, personally, am tired of reading the same thing over and over again, and I wanted to see something different. I enjoy taking a stereotype and turning it upside down.

Jonathan and Julia had a turbulent childhood lived largely off the grid. Did your own childhood in the Children of God cult in any way inspire their origin story?

Yes and no. No, in the sense that I obviously was raised in an unusual situation, but clearly not like that. Yes, in the sense that I’m a third-culture kid. Third-culture kids are like military brats or children of diplomats who don’t really belong to their parents’ culture because they’re detached from their home passport countries, but they don’t really belong to the country they’re living in, either. People like this have an affinity for each other, because they relate to the idea of not having a home, to constantly being uprooted. I relate to people who didn’t grow up in a stable environment. In that sense, I have a lot of wealth to draw on, but the characters are not fashioned after me or my childhood or anything that I lived.