Here’s a post at Nathan Bransford’s blog: Build mysteries around whether characters will succeed or fail
This is a fine post, but it’s not really about building mysteries; it’s about avoiding confusion.
Here’s a bit of the post:
You’ll often see novels start off with something that nominally feels high stakes, like a character running through a dark forest as fast as they can… only the author doesn’t tell us why they’re running. The author wants us to wonder: why is this character running as fast as they can through the forest? Mysterious, right? But it’s downright confusing to not be given more information that that …
Yes, I think that’s true. This sort of beginning often has the effect of opening in a “white room” — a setting that lacks all description. This is true even if the author spends many sentences describing the dark forest, because without context provided by the protagonist, the dark forest might almost as well not exist.
I will grant, a skilled enough author can make a dark forest so evocative that it might draw in the reader even without context for the protagonist’s flight. But it’s a challenge to make that work and most writers would probably be better off not trying. Establish the character along with the setting; that’ll work better, generally speaking.
Nathan isn’t saying that a flight through a dark forest can’t work; his point is that vagueness is a flaw.
Vague mysteries are missed opportunities to build suspense and anticipation. What’s the better mystery: Why is this character running through the forest? or, Is this character going to avoid getting ripped to pieces by a nasty moon demon? … When we only find out what was really happening after the fact, it invariably feels like a letdown. The reader’s reaction is more like: “Yeah… had I known the situation was life or death, I might have been worried. Instead I was just confused.”
That’s a good point to make!
I suppose the broader point here is that it’s hard to tell what “in media res” means and how to start your novel when a lot of advice basically goes “Start by setting something on fire.” A good rule of thumb, it seems to me, is that no matter what you set on fire, you’d better establish your protagonist too. And, I think, Nathan Bransford would add, also the basic idea about what’s going on.
That’s certainly a lot to do in the first paragraphs of a novel! But, yes, just setting something on fire, or sending someone racing through a dark forest, probably isn’t enough.