There is an oft-quoted line from Chekov: "One must not put a loaded rifle on the stage if no one is thinking of firing it." The corollary is: If you fire a rifle in the third act, it better have been shown to us in the first.
Which means: there needs to be a set up for plot points, particularly those points that are the resolution of the plot. Proper set up means that even though the reader says "aha!" they don't say "where the hell did THAT come from??" (or if they do, they can re-read to find the answer.)
This is a helluva lot harder than it looks and an author who does it with elegance and subtly is a skilled marksman indeed.
If you want to see a gorgeous example, look no further than BENT ROAD by Lori Roy. BENT ROAD is nominated for an Edgar Award in the Best First Novel category. Since my Fabulous Client Steve Ulfelder is also nominated, I wanted to read all the books in the category.
BENT ROAD is not a novel I would have picked up if left to my own devices, which may be proof positive that I am an idiot.
BENT ROAD is an amazing novel. And my appreciation of the artistry of the author increased about an hour after I read it when, standing in the shower, I remembered a scene in a cafe. I won't tell you anymore about it because I want you to experience that book like I did. Read it with raw eyes.
Then, if you are a writer, go back and read it again and watch how Lori Roy sets all the pieces in place. Once you know, you'll see it.