Getting into this book was initially a bit of a challenge because of how repetitive the writing was in the early chapters. While I can appreciate the stylistic effect the author was aiming for, constantly seeing entire passages basically twice with a bit of  variation just made my brain check out. This approach to comparing and contrasting the two MCs was fun on the first time and tolerable on the third, but after a few pages it was just. Overkill territory.

Once Avery and Zib were out of their ordinary town and over the wall, though, and the story kicked off in earnest, the prose turned a lot more engaging and easy to follow. It was from that point on that I started getting hooked. The worldbuilding here is an absolute delight: a dark, twisted version of Oz, basically, with the Tarot-themed monarchs and the kind of logic that works precisely because it shouldn't. Technically, it's a tie-in for Seanan McGuire's adult urban fantasy Middlegame, and I feel like while I've caught a few clever connections, I've missed a lot more (it's been years since I read that one). But I feel like this book works on its own pretty well. It also feels at least loosely related to the Wayward Children series, if only because of the "portal fantasy + kids" theme, but also there are just... *gestures vaguely* Vibes. There's nothing that explicitly proves the Up-and-Under fits into that specific cluster of words, but also, if Avery and Zib turned up at Eleanor West’s Home for Wayward Children after their adventures, I feel they wouldn't be out of place.

What really captivated me was how the narrative plays with storytelling conventions in so many ways. The Hero's Journey structure is there in full view, almost on the nose, and then at crucial moments there are small, clever twists that keep it intact but also infuse the whole thing with new meanings. I also liked that kind of self-aware nature of the narrative, with all the asides about the nature of stories and how they work. I do wonder if this book truly makes a good middle grade story, though, because I thought that many of the elements I found most engaging might fly over kid readers' heads. Then again, perhaps I'm not giving kids enough credit. And surely there are some more whimsical elements of the book that I kind of glossed over while lapping up the meta commentary parts.