Mislaid in Parts Half-Known

 Mislaid in Parts Half-Known by Seanan McGuire, 146 pages.

Antsy, older than she ought to be, is the newest student at Eleanor West's School for Wayward Children. Fitting in is a struggle, since none of the students know that inside her teenage body she's still just a nine-year-old girl. But the other students take a much stronger interest when they realize that Antsy's talent for finding any lost thing could extend to their lost Doors as well. So Antsy and her new friends (which include both the old cast and the escapees from the Whitethorn Institute) escape through a door and go on a jaunt through worlds as they consider what it means to go home. 

This book was a more direct continuation than any of the other books in the series so far. Despite the large cast, it felt like less of an ensemble book than most of the forward plot books. The inciting incident also felt a little bit contrived. That being said, the writing in this series remains top-tier, and I continue to really like Antsy as a character.