I don't remember all that many details from the preceding book in this series, which is a pity, in that it would have helped me better understand this one. Whatever, Flavia is sent into exile in Canada. Sent to Miss Bodycote’s Female Academy in Toronto to be exact. She is a member of a mysterious "cult"/"spy ring"/something known as the Nide. But no one can let on that they're members of this group, other than hinting at something about pheasant sandwiches. It's all oblique.
Anyway, the day she arrives at Miss Bodycote's Female Academy, a body falls out of her chimney. Who is it? Could it be one of the former students who disappeared mysteriously? Suffice to say, Flavia wanders around a lot, thinks about chemistry a lot, and even does some experiments. Eventually she figures it all out, but for some reason, is deemed not Miss Bodycote material, and is shipped home, where, we presume, she'll have another adventure with her chemical laboratory and sisters.
I gave this 4*, but it should only be 3*+.
Interestingly, two days after I finished this book, my spouse and I were watching a video of Dorothy Sayers' Strong Poison
. Towards the end, they set up a chemical apparatus to do arsenic analysis, almost exactly as described by Flavia's analysis in this book. Pretty fun to read about it, and then see it performed in "real life".
Another weirdness is that all the rooms at Miss Bodycote's Female Academy are named after famous women. Flavia lives in Edith Cavell. Edith Cavell was a nurse in WWI who saved people no matter what side they'd taken. She was executed. The very next book I read had a reference to Edith Cavell in it, something about Edith Cavell in drag.