As a writer, there is no end to the stories I have in my head. The main hindrance to those stories coming to be is time. There just isn’t enough of it.
Oh, and money. There’s never enough of that either. And if I’m to be honest, money becomes the most important factor when I consider how deep a series will go, sadly.
You see, if the book isn’t pulling it’s weight then that’s an indicator that the book doesn’t have an audience and thus doesn’t deserve to go on and on and on.