Roughly, the action of a character should be unpredictable before it has been shown, inevitable when it has been shown. In the first half of a novel, the unpredictability should be the more striking. In the second half, the inevitability should be the more striking.
Elizabeth Bowenin my experience one thing you don't learn from is anything anyone set up to be a lesson; what you are to know you pick up as you go along.
Elizabeth Bowen