You have to decide what is extraneous and what is central. There is always more to tell. If you want to have a finished product, at some point you have to say "enough."
As you work, the mood grows on you. There are certain images which suddenly get hold of me and I really want to do them. But it's true to say that the excitement and possibilities are in the working and obviously can only come in the working.
I'm not sure if we're going to or not because what happens is I'd always love to see certain characters back, there's so many. Some of it has to do with, if we want them back, are they available and the other aspect is do they fit with the storyline we're telling.