Getting Double Jack to work took a lot of time and energy. After writing it, I set it down. Sometime later, I would pick it up, throw out most of the chapters, then completely rewrite. The next draft, I would keep a few chapters, but throw out the rest. I went down many blind alleys, slowly learning what made this book tick, what made the genre tick, and discovering in every draft that I didn't yet understand the rules of the work.
I hadn't written in first person this extensively before. I had written a short story here and there, but not an entire novel. So before I even began, I had to get that voice right. I didn't want Jack's memoir to feel like a hardboiled detective, so I couldn't even begin until I could get a different voice in my head.
What does a fantasy novel set in the 1920's even look like? In truth, we know, because we have fantasy stories from back then. As we don't need any more of those, I didn't think that I actually wanted to write something like that. I certainly didn't want to write something like Lovecraft. What I wanted was something that felt more like F. Scott Fitzerald, so taking a few years, I casually read most of his books. Whatever I produced, I wanted it solid enough to stand alongside a Fitzgerald novel without shame. At the same time, I didn't want it to actually be a Fitzgeral novel. What I wanted was for it to feel like it came from the same time period. I wanted it to feel like the sort of fantasy novel that one of Fitzgerald's literary contemporaries might produce.
There are certain things that I didn't want. I didn't want steampunk or dieselpunk. I have no ill will towards either genre, but I felt that this memoir, this mildly noir style recollection, would go astray with if I made it one of those two genres. However, my research and a few insights revealed to me that, beyond all comedy, that the 1920's were already post-steampunk. In real life, humanity had actually produced the Victorian steampunk society, and now it was busily producing a real dieselpunk society, with radios, airships, plastics. The old steam society was literally being superceded by new fashions, trends, and vocabulary. The even amazing more truth was that the 1920s were an age of science fiction, so I didn't need to invent anything at all. I wanted the novel to feel like that, leaving one age to enter another.
One point where I wavered was whether the novel would take place in the United States or a fantasy world that looked and felt remarkably like the United States, just like most fantasy worlds feel medieval. Although I leaned very strongly to making this world entirely artificial, setting it in the US gave my readers a geography, and gave me access to all our existing history, maps, culture, and politics. By making the world familiar, I didn't have to explain vast swaths of backstory. Because I was already familiar with Baltimore, I set the novel in that city. Because of how history progressed a little differently, it's not quite the Baltimore of our own past, but it has enough in common so that you know it's the same place.