I do not invent characters. There they are. That's who they are. That's their nature. They talk and they behave the way they want to behave. I don't have a character behaving one way, then a point comes in the play where the person has to either stay or leave. If I had it plotted that the person leaves, then the person leaves. If that's what the person wants to do. I let the person do what the person wants or has to do at the time of the event.