There is a secret genre whose defining trope is that the world’s divided into fiefdoms. Like, every geographic area is the absolutist domain of some powerful person, and all the domains are small enough – or transportation’s fast enough – that you can visit multiple domains in one day. I usually have this thought because of vampire romance or urban fantasy or superhero or cyberpunk plots, and sometimes high school comedy plots, but today it struck me how much this defines the California noir plot: all the California noir detective ever does is motor between different castles.