And a story equally needs what Jill Paton Walsh calls a trajectory—not necessarily an outline or synopsis to follow, but a movement to follow: the shape of a movement, whether it be straight ahead or roundabout or recurrent or eccentric, a movement that never ceases, from which no passage departs entirely or for long and to which all passages contribute in some way. This trajectory is the shape of the story as a whole. It moves always to its end, and its end is implied in its beginning.
