The trouble, I have discovered, with writing fictional characters is that they have a habit of trying to take over. Like Pinocchio, they all yearn to be real, to cut the strings by which you control them.
It starts off well enough, you write something to define who they are, what they look like, how they fit into the story and that’s straightforward enough. Great, you think, this is easy. So you sit down and write some dialogue for them and suddenly they are saying all sorts of things that never entered your head. You think, fine, enough dialogue, lets do some action, may be a description of what’s happening, a bit of ordinary stuff, scenery and that. Next thing you know, they are trying to muscle into the limelight and if that’s not enough, they have you writing all kinds of salacious and other nonsense. Then there are the characters that have no business being there at all and just wander in off the street for a look around before disappearing again.