When I published Exit Velocity last year I had to choose a category for it, so that bookstores would know where to place it. This pertains to online bookstores as well as brick-and-mortar bookstores. I wanted to choose the category of “social justice,” but there was no such choice on BookBaby or Amazon. Because I couldn’t choose “social justice,” I then tried to determine whether I should choose “political fiction” or “science fiction.”

Political fiction usually directly criticizes an existi...