Plot Twists 101

If it's okay, I'm going to go ahead and ruin The Leper of St. Giles for you. It's not like you're going to read a medieval murder mystery novel from the 1980s just because your favorite writer recommended it. Right? If I'm wrong, I advise you to skip this week's blog.
I'm bringing up The Leper of St. Giles because it has one of the greatest plot twists I've ever witnessed. Towards the beginning of the book, we're introduced to a mysterious, masked leper. We learn that he is called Lazarus, and that he never stays in one place for long, but rather roams throughout England. He doesn't come into the story much, but he ends up helping someone hide from the authorities--which, in this case, is a good thing.
It's not until the very end of the story when we learn that Lazarus is actually Guimar de Massard. He fought alongside protagonist Cadfael in the Crusades, but contracted leprosy in the Holy Land. He sent word to his family saying that he had been killed in combat. When he learned he had a granddaughter, he returned to England and actually had a greater hand in the plot than we first realized.
I wasn't expecting that at all.
Plot twists are joys to write. They're like gems--you don't get to write them often, maybe one or two per book if you're lucky. But you feel a certain sense of sadistic joy. You know how it feels to read a plot twist. You're shocked, maybe a bit betrayed, and you can't put the book down before you find the answers to all your questions. And knowing that you've just put all those emotions in your readers is one of the best feelings in the world.
But if a plot twist isn't done well, it's not worth writing at all.

There are a couple of guidelines for writing plot twists. First, your plot twist can't come out of thin air. Your character can't be in perfect health throughout the story and suddenly be diagnosed with stage four cancer. A character who's dedicated their entire life to a certain cause won't suddenly turn evil overnight. And having the character wake up in Chapter 10 and realize that chapters one through nine were all a dream is plain wrong. Unless they were in a coma or you're writing some sort of psych thriller.
For example, in Cressida Cowell's How to Cheat a Dragon's Curse (more spoilers ahead), protagonist Hiccup spends the entire book thinking that his best friend Fishlegs has been stung by a poisonous dragon and is dying. And Fishlegs is, indeed, very ill. But the second-to-last chapter, we find out that Fishlegs is fine right before Hiccup nearly faints from what is revealed in the last chapter to be--you guessed it--the sting of the poisonous dragon. He was fine for the entire book, with the exception of a single reference to a sore throat.
In this example, we learn why the second guideline--foreshadowing--is important. Now, you need to be careful with foreshadowing. It's easy to give away too much, but as demonstrated by Cressida Cowell, it's also easy to give nothing away at all. Is it a stretch to believe that Fishlegs's illness is caused by anything other than a dragon's poison? Not at all. But asking us to believe that Hiccup is dying while he's quite obviously in good health is another thing altogether. Maybe, though, if we'd have had another reference or two to Hiccup not feeling well, we'd be more inclined to believe in the twist ending.
What's your favorite plot twist in a book, movie, or TV series? Let me know in the comments below! God bless you, dear readers, and don't forget to like us on Facebook!