Okay, I'll admit I'm trying to up my cred as a children's author by inventing my own word. Spread it around.
PREINFORCE. It means foreshadowing. Only, the thing is, "foreshadow" isn't actually very descriptive or evocative of it's function. I just feel like, as writers, our own tools ought to embody our art, and not simply be flowery. Amiright?
So. Russian author Anton Chekov is famous for having said, "If in the first act you have hung a pistol on the wall, then in the following one it should be fired. Otherwise don't put it there." The point he was trying to illustrate is basically don't put anything in your story that does not eventually serve a purpose. This concept is known widely as "Chekov's Gun."
In broad strokes, this is an excellent rule. But Chekov was talking about plays, not novels. In novels, writers often add a line of dialogue or a sentence of description simply to evoke a mood or to create a beat in the pacing. There will inevitably be things mentioned in a novel that are never revisited. Particularly in this age of writing in anticipation of the eventual sequel.
The other thing about this kind of thinking is that it occasionally leads a writer to make up a reason to justify something they really like earlier in their book, just so they can keep it. I'm not too proud to admit that this exact kind of thinking led to the villain in my and my daughter's WIP.
But this is not actually the same thing as foreshadowing. The art of foreshadowing requires a skill for thinking backwards every bit as much as thinking forward. In fact, to be really effective, the actually event you are foreshadowing should be fully established in all its glorious minutia before you go back and sprinkle in all of the supporting details. The process of adding in those details on a later pass is what I call "preinforcing." Like all good words, it means precisely what it sounds like -- you are reinforcing in advance. Burying clues along the way that do not look like clues.
That's the difference between foreshadowing and preinforcing. With foreshadowing, a writer puts something in their story in anticipation of a later event which has not yet been written. Or, as I've already talked about, they put in something that they later decide to expand upon. Preinforcing, on the other hand, is deliberately preparing your reader to properly experience an event you've already written.
How does one do this? Well, the fact that all of the details are already in place makes it much easier to be subtle. Foreshadowing before you've written the later scene must necessarily be done in broad strokes. Whereas going back and seeding subtle details is really only possible when the tiny details have been established. Then, you can evoke a mood or a color or a scent early on which will fit in so smoothly that it never suggests it is planted to foreshadow some future event.
In our WIP, our main character discovers in chapter 15 that she is descended from trolls. One of the qualities of pure-blood trolls is that sunlight turns them to stone. Having established that, I went back and preinforced this by giving her a sunburn and flaky skin, which she is still experiencing when she puts 2 and 2 together. I preinforced that by having her forget to put on sunscreen and worrying about her skin in the previous scene. And I preinforced that by having her mother tell her not to forget sunscreen because she burns so easily, way back in chapter 1. In every one of these cases, those little bits of additional information fit perfectly into the tone, mood, and pacing of the moment. In the middle scene, she has decided on the spur of the moment to sneak out of the house, hop on her bike, and ride across town to confront her nemesis. On the way, she realizes that in her haste she forgot to put on sunscreen and on top of everything else she's going to have to deal with a sunburn. Later, when she is depressed because things did not go well, she sullenly scratches her sunburned arm and notices the flaky skin. So when she starts to pile up the evidence that she is troll-born, her sensitivity to sunlight has already been well and subtly established. It is not something that had been presented early in the story like a pistol displayed on the wall.
The best foreshadowing is the kind you never see coming. And to achieve that, you have to set it up carefully and deliberately. You can do it in advance, but to do it with finesse it is usually better to go back and add it.
Say it with me: "Preinforce." Spread the word.