When you think about it, a plot in a novel is ultimately all about character change. Without the central character undergoing a transformation, there would be little point in writing or reading fiction at all.
Seeing a fictional character we care about undergo a momentous experience (in the form of the novel's plot) and emerge changed as a result of that experience (hopefully for the better), is somehow life-affirming for writer and reader alike.
And so, when plotting your own novel, never lose sight of the fact that the way your central character is at the beginning and the end, and the difference between the two, is of paramount importance.
(This change, incidentally, is often called the character arc.)
Have you noticed that, in real life, people don't tend to change very much at all. By the time they reach adulthood, a person's character is more or less set, and that is the way it stays.
Oh sure, they might make the occasional effort to change - to be more tolerant, perhaps - but sooner or later they slip back into their old ways.
That is why fiction is so much better than real life...
...and the changes tend to stick, too (or at least us readers like to imagine that the character change is permanent once we have closed the final page of the book).
Of course, not all characters undergo transformation in a novel. It is usually only the leading man or woman who undergoes this change. The rest of the fictional characters remain precisely how they were at the beginning.
So what I am about to say really only applies to your protagonist. (In fact, a novel's protagonist, by definition, is the one who is transformed.)
"In reality people change, however slightly, as a result of their experiences. There must be some sort of conversion brought about by the events you devise; the central character must develop along with the novel and acquire new attitudes - preferably wiser ones."
- Dianne Doubtfire
In a nutshell, the theory goes as follows...
Changes are triggered in a character when they undergo a momentous event.
They are unlikely to be changed in any significant way by a trip to the seaside. But if they save someone from drowning while they are there - or fail to save them - they will almost certainly arrive home with their internal make-up altered.
Now, when a fictional character undergoes such a momentous experience, there are three possible outcomes...
Imagine a story in which a character wakes up in the morning and goes to work to discover they have been fired.
Are they upset? A little, at first - but at least they can now go home to watch some golf on TV. So they go home and switch on the golf, completely unaffected.
If characters aren't altered by the novel's events, not even a little, then the events they experience are simply not big enough.
By "big," I don't mean there has to be explosions and car chases. A scene showing a family sitting down for a meal has just as much potential for drama as the same family aboard a hijacked airliner.
It is simply that the events, whether large or small, dramatic or quieter in nature, should have consequences for the characters concerned.
Look no further than Ebenezer Scrooge for the perfect example of this kind of change...
Now, I am not having a dig at Dickens here. (He is one of my favorite writers, and A Christmas Carol is one of the most perfect stories ever told.
But in most novels, particularly in the 21st century, having the protagonist change so suddenly and so completely would frankly be laughable.
If you are writing a modern fairy tale, fine. If not, go for the third option...
Aim to be as light-handed as possible when charting your protagonist's change.
And that really is the best way I can explain it. Go for more of a slight shift in the main character's consciousness than a Scrooge-like total transformation and you won't go far wrong.
Perhaps the best thing is to illustrate all three options with an example. So let's return to our family man whose young daughter has been kidnapped.
The novel begins with a scene showing the happy family all together: the man cooking dinner, his wife pouring two glasses of wine, their daughter doing her homework at the kitchen table. The man's life is the very essence of contentment.
But then the daughter is kidnapped on her way to school the next morning, and the husband and wife go to hell and back in their efforts to find her safe and well. In the end, though, they succeed.
Now, for the bulk of the novel, the husband is clearly not the happy and contented man we saw at the beginning. (We wouldn't expect him to be with his daughter missing.)
The question is, does he return to his old self once his daughter is safely home?
The final scene (in which we will find out the answer to this question) is a bookend to the opening scene: father cooking, mother pouring the wine, daughter doing her schoolwork. Here is how the final scene plays out using our three options...
There is no difference whatsoever between this closing scene and the opening one. The man is as happy and as contented now as he was then, and the trauma of his daughter's kidnapping has left no scars whatsoever.
Which rather begs the question, What was the point of telling the story at all?
The man has been to hell and life will never be the same for him again. When his wife hands him the wine, he swallows it in one gulp and demands a refill. When his daughter tells him the chicken is burning, he dumps it in the garbage. His wife tries to comfort him and he drops to his knees, weeping.
Unrealistic? Maybe, maybe not - but certainly melodramatic (and that's not a compliment).
This one is a cross between the previous two...
There is nothing melodramatic in this final scene, and on the surface everything seems happy, just like it was at the novel's start. The man is different, though - there is now an icy shard of fear and distrust in his heart that wasn't there before.
The family is sitting at the table, eating the meal, talking and laughing. But when the man hears a noise outside, he stares at the window with wide, fearful eyes. It was only a dog, the wife says, and things return to normal. But as readers we know that things can never quite be normal again.