Where It All Goes Down
An Unpleasant Alternate Reality
Real talk: The book's setting is one big, complicated bummer. Witch and Wizard is set in a world that seems to have recently fallen under the control of an evil totalitarian regime run by The One Who Is The One. We don't know many details about what happened; there are some vague references to recent elections and consolidations of power. What we do know is that the world is a pretty miserable place—we're talking no free speech, no art, and no chewing gum. Really.
On the surface, this world looks a lot like ours. One big difference is the whole magic thing, of course. But another way the book makes itself "other" is by altering the names of real musicians and artists (for example, Radiohead is referred to as "Toasterface," Frida Kahlo is "Freida Halo," and so on). And because of this, it seems safe to say the setting is an alternate reality that is more or less contemporary with ours.
Where in the World
The world of the book can be divided into two parts: the Overworld and the Underworld. The Overworld is the regular world that Whit and Wisty have always known. It's largely under the control of the New Order and includes two prisons and the City of Progress. When Whit and Wisty escape from prison, they go to an area called the Freeland, which is (as its name suggests) not under the control of the New Order. There, they squat with hundreds of other children in a bombed-out department store called Garfunkel's.
Whit and Wisty were introduced to the Underworld by Whit's dead girlfriend, Celia. As a Half-light, Celia lives there in the Shadowland most of the time, though it isn't exactly homey. It's super foggy, cold, and scary—and its inhabitants include the Lost Ones, who seem like a cross between zombies and demons. Humans aren't exactly supposed to hang out there, but Whit and Wisty had to pass through during their prison escape. They travel in between worlds using portals that are constantly changing positions. This causes some small amount of stress, as you can imagine.
The (Mysterious) Five Levels of Reality
One thing that's confusing about the book is the five Levels of Reality. We know they exist, courtesy of The One Who Is The One. He tells Whit and Wisty that the Fourth Prophecy is that "they must visit all five Levels of Reality, which no one before them has done" (98.12). So, are two of the levels the Overworld and the Underworld? Does the Shadowland count as a separate level? This is all unclear, so for now, the Levels of Reality will have to remain a mystery.