Some writers don’t know what’s going to happen next when they sit down at their computers. Others follow their outlines religiously. Sir Terry Pratchett, author of the Disc World books, compared his process of writing novels to wood carving on his website:
You find the lump of tree (the big central theme that gets you started) and you start cutting the shape that you think you want it to be. But you find, if you do it right, that the wood has a grain of its own (characters develop and present new insights, concentrated thinking about the story opens new avenues). If you’re sensible, you work with the grain and, if you come across a knot hole, you incorporate that into the design. This is not the same as “making it up as you go along”; it’s a very careful process of control.
I really like this idea of working with the grain and incorporating knotholes into the design. On more than one occasion I’ve come to a surprising realization at the same moment as my main character. In my soccer novel Defending Irene, for example, I realized that the rather goofy keeper was the son of the strict coach. That opened up all sorts of things to me. In an unpublished manuscript, my main character and I literally ran into a new character at the exact some moment. Sofia definitely qualified as a knot. I thought that I might have to cut her out completely as she tried to take over the story. Instead, I found ways to incorporate her into the design in a way that echoed to my main theme.