Kansas, 1985; Kansas and surrounding states, 2009
This isn't the Midwest, American-as-apple-pie place from American folklore. This is Gillian Flynn's Midwest, a place where the towns are falling to pieces—pawnshops, run-down houses, Dairy Queens—and so are the families. And when these families fall apart, they really fall apart.
As in every Midwestern town, there's a water park on the outskirts (22.13). As kids in 1985, though, the Day children don't get to go to the waterpark. They're too busy trying to make ends meet. In fact, Patty and the kids wonder if "anyone's going to take the farm away at some point?" (4.10).
Of course not. Farmers pull together, Grapes of Wrath-style, right? Yeah, not here. In this world, "farmers who weren't going under never had sympathy" (6.25). The other people would be almost glad to see them gone.
Throw Satan into the mix, and the Day family becomes a guaranteed pariah. 1985 is the height of the "Satanic Panic" (5.29), a time when "the whole psychiatric community, the police, law enforcement, the whole shebang—they thought everyone was a Devil worshiper back then. It was… trendy" (5.31). Nowadays, the whole thing has been revealed to have been completely unfounded.
All this did was spread fear of people who were different, whether they were lower class, listened to heavy metal, wore all black—or all of the above, like Ben. The Satanic panic gave people something invisible to blame differences on and discouraged them from actually trying to understand those differences. Yeah, thanks for nothing, Satan!
Toto, I Wish We Weren't in Kansas Anymore
Kinnakee refers to itself as "the heart of America" (8.3). Home is where the heart is, right? But as Libby immediately tells us, "Kinnakee was working from bad information" (8.4). It's not the geographic center of the United States, after all. Yeah, well, facts schmacts: Kinnakee continues to call itself that, anyway.
Gillian Flynn makes every effort to remind you that Kansas was a cesspool in 1985, and it's a cesspool now. Does she do this to add to the general unlikeable atmosphere of the novel? Or is Kansas actually that bad? Libby's present-day neighborhood "doesn't even have a name, it's so forgotten. It's called Over There That Way" (1.9). In this instance, the broken-down forgettableness of the setting matches Libby's mood. She is broken down, and she's starting to be forgotten.
Another setting that matches the mood is the prison in Kinnakee, Libby's hometown, "which had turned itself into a prison town without my permission" (8.13). It's a literal prison, housing Ben, and it's a figurative one too, because Libby is a prisoner to the tragedy that happened to her so many years ago.
Unlike Kinnakee, Libby learns that what happened to her in the past will not define her forever.