Spotswood’s debut and series launch, Fortune Favors the Dead (Doubleday, Oct.), introduces a pair of female private investigators in 1945 Manhattan.

Where did you get the inspiration for Lillian Pentecost, an aging gumshoe who’s living with multiple sclerosis?

Lillian was of course inspired by Holmes and Poirot and Marple and Nero Wolfe and all the other detectives who rely on brain over brawn. But she’s also a product of my years in medical journalism learning about chronic illnesses and the impact they have on a person’s life. I was acutely aware that there was a dearth of that kind of representation, and I wanted to create a brilliant, capable woman who’s not just dealing with the impact of MS but thriving in spite of it.

Willowjean “Will” Parker is very much the Archie Goodwin to Pentecost’s Nero Wolfe. What makes Will different?

I adore Rex Stout’s novels, but Archie and Nero arrived full-formed and never really changed. Will, a bisexual runaway who spent years with a traveling circus, is still growing. She’s learning the trade, and making a lot of mistakes, all while wrestling with a certain amount of personal trauma. We get to see Lillian and Will accumulate their scars and then watch as they help each other deal with the pain.

Did you have trouble immersing these characters into an overtly sexist period when women had rigidly defined gender roles?

There were women working well outside the gender norms in 1945, including detectives. The challenge wasn’t fitting them into the time period, but always keeping in mind what additional hurdles and barriers and casual (and not-so-casual) misogyny Lillian and Will would face.

How do you want to change readers’ perspectives with this novel and series?

Fortune Favors the Dead occurs in this postwar bubble, this cusp of great change where the country is still euphoric over victory and is just starting to turn its gaze inward. We think of the 1950s as the beginning of this golden age for America. But that postwar, suburban ideal came at the expense of a lot of people. Anyone who fit outside that cultural norm got left out in the cold, if not stomped out entirely. That’s a theme I hope to come back to again and again—who is the world really built for and who gets sacrificed along the way.