Harrow the Ninth (The Locked Tomb, #2)
by Tamsyn Muir
This book is divisive, and whether you like it seems to come down to how much you enjoy being confused. I love baffling but thoroughly thought out story structures, so I was into it.
Both camps, however, will love the part in the middle of the book where Harrow stops sleeping and learns to cook. I screamed.
2025 reread: I was nervous for a bit that I'd lost the knack of rereading. Still got it!