Suspense and... surprise! Building up to unexpected revelations is the central device used by Charlotte Brontë in her novel Jane Eyre
(I hope I don't need to say "spoiler alert" here. I assume that if you've heard anything at all about Jane Eyre, you already know what Jane's big surprise was. If not, and you don't want it spoiled, go read the book before reading the rest of this essay.)
Part of creating an effective plot twist is designing a plausible explanation for why the surprise information wasn't already known. For example, Jane didn't know about her uncle and cousins on her father's side because her spiteful aunt deliberately kept the information from her.
Then there was the time when Jane was so in love with Mr. Rochester, but she was convinced that he was planning to marry the beautiful Miss Blanche Ingram. One day Jane got the wonderful surprise that Mr. Rochester never had any intention of marrying Miss Ingram, and, in fact, he wanted to marry Jane instead! And why was that a surprise? Because Mr. Rochester actively pretended to court the penniless aristocrat for weeks (and had ordered Jane to sit in the room every evening and watch him flirt with her beautiful rival) -- expressly for the purpose of making Jane jealous.
Wow! what a.... romantic...(?) thing for him to do. That's almost as romantic as the time when Edward Cullen showed Bella that he knew where her key was hidden, and told her he'd been sneaking into her bedroom every night to watch her sleep. (My friend Holly said that the fact that both Mr. Cullen and Mr. Rochester have the same first name is no coincidence.)
The biggest plot twist -- the revelation that Mr. Rochester had been keeping his first wife locked in the attic and pretending like she didn't exist (so he could marry Jane without her knowing that the marriage wouldn't be legally binding) -- now that requires one doozy of an explanation!
Mr. Rochester can't very well say that he loved his first wife -- and was devastated when she started losing her mind -- but then a few years later decided he deserved a new wife. That would make him a bit of a fair-weather husband, and it would raise the obvious question (which was actually addressed in the book) of what would happen to Jane if she one day lost her marbles. Would she find herself locked in the attic with Mrs. Rochester #1 while Mr. Rochester galloped off to find himself a third?
Certainly not! So he needed a better explanation.
As Mr. Edward Fairfax Rochester explains it, the horrible Miss Mason tricked him into marrying her for her immense fortune when he was a penniless second son, not in line for any inheritance of his own! Their respective families rushed them into marriage when they had barely met -- and in particular, no one had informed him of her family's history of insanity.
Soon after the marriage began, Mr. Rochester concluded that his wife was a wicked, despicable creature. Then, when his father and his older brother conveniently died -- leaving him with his own fortune so he didn't need hers anymore -- boy did he regret being saddled to her!
There's a bit of a problem with this story, and perhaps you've noticed as I did:
Given that Mr. Rochester hardly knew his wife (and inasmuch as he did know her, he hated her passionately), and given his obvious personal stake in the situation, he could not be trusted to sincerely keep her best interests at heart when deciding on an appropriate treatment when she started showing signs of dementia.
Would it be good for Mrs. Rochester to be taken to a foreign land -- away from everyone and everything she's ever known -- and locked away in isolation in the secret chambers in the top floor of her husband's mansion? I'd say that's a pretty obvious "no." But in those days the husband was the owner and the wife was property, so no one had any grounds to second-guess this ill-advised plan.
With Mrs. Rochester hidden away, poor Mr. Rochester had no choice but to wander the glittering social scene of the wealthy class of Europe, hiring beautiful mistresses to comfort his lonely heart in France, Italy, and Germany. But as tragic as this disastrous marriage was for Mr. Edward Fairfax Rochester, for the heiress (Bertha) Antoinette Mason it was infinitely worse.
Eventually Mr. Rochester decides that his first marriage is so wrong on every level that it should hardly be considered a marriage -- and he should be able to get on with his life. I totally agree with him on this point. I would recommend the merciful modern solution to such tragedies: a divorce. One where a judge would award each party a fair settlement. Sadly, in their society, that option did not exist.
It's a weirdly glaring omission in the book that when Mr. Rochester decides to move on with his life, nobody asks what should become of his wife's fortune. If he's decided that he can remarry because his first marriage is void, then shouldn't he, I dunno... give it back? He could give it to her brother, for example, and place her in her brother's care. Or he could use the money to create an independent trust for her that would be managed by experts to see to it that she passes the rest of her days in comfort and safety with the best possible care.
But no. Mr. Rochester gets the money and Mrs. Rochester gets incompetent surveillance in the secret chambers of the house (where her occasional glimpses of her husband courting other women further enrage her madness) until finally -- luckily for Jane and Edward! -- she commits suicide and stops being an obstacle to their happiness.
All of that is just reading between the lines of the book Jane Eyre -- where Mr. Edward Fairfax Rochester is intended to be sympathetic and even lovable. But clearly I'm not the only one to notice that his story in his own words is a little fishy, and if it were a true story, there'd be another side to it.
The challenge of creating a fictional other side to the story was taken up by the author Jean Rhys in the novel Wide Sargasso Sea
For many years, Jean Rhys has been haunted by the figure of the first Mrs. Rochester [...] it is in no sense a pastiche of Charlotte Brontë and exists in its own right, quite independent of Jane Eyre. But the Brontë book provided the initial inspiration for an imaginative feat almost uncanny in its vivid intensity. From her personal knowledge of the West Indies, and her reading of their history, Miss Rhys knew about the mad Creole heiresses in the early nineteenth century, whose dowries were only an additional burden to them: products of an inbred, decadent, expatriate society, resented by the recently freed slaves whose superstitions they shared, they languished uneasily in the oppressive beauty of their tropical surroundings, ripe for exploitation.
As you might guess, the story is incredibly sad and disturbing. And it is brilliant in the way it so perfectly fits with Edward Rochester's story and character. Some of the components of the story don't exactly match what he said. Yet if you read Wide Sargasso Sea as the back-story, the tale he recounts in Jane Eyre is exactly the way you'd expect him to tell the story to himself ten/fifteen years later, given all of the decisions he'd made in the meantime.
Naturally, in Wide Sargasso Sea Edward Rochester is not cast as a black-hearted villain, cruelly calculating how to further his own interests at the expense of others. The story presents him just as he'd described himself: as a naive and inexperienced young man who'd been raised in wealth, expecting to be obeyed by all those around him. Consequently he was unwilling and unable to understand the frighteningly unknown country his father had sent him to, much less the troubled girl from a troubled family that came with it.
Now, despite all I've said here, I think that Jane Eyre is a remarkably feminist story for its time. Jane is portrayed as interested in marrying for love -- but absolutely not on anything less than her own terms. She'd rather support herself on a small salary running a school for girls than give up her independence for wealth or adventure.
Jane would have been more than happy to accompany her handsome new-found cousin on his mission to India as a colleague, but if propriety demands she marry him to do it, the deal is off. Similarly, when Mr. Rochester offers her his villa in France -- where nobody has to know anything of their situation -- she'd rather run away in the night than risk being tempted into accepting the proposition. (This was mostly on religious principle, but she was probably also influenced by what Mr. Rochester had said about how awful it is to take a mistress: "to live familiarly with inferiors is degrading.")
It's true that their romance was largely built on eroticizing the power dynamics of the master-servant relationship. Yet when Jane finally agrees to marry Edward, it's only after she's demonstrated that she doesn't need to be married to him, and she can approach him as an equal.
Of course since not every girl gets to have an unknown rich uncle appear just in time to die and leave her a fortune, it would have been nice if Jane could have been on equal footing with Edward simply on the principle that women are people too, and have rights -- rights like the right to own property regardless of marital status and the right to sue for divorce, when necessary.
The happy ending is that this book probably had a big influence on shaping people's attitudes towards divorce, which led to changing the laws.