Post-finale reread: I beta read and plot-doctored this book the first two times I read it, so it was almost impossible for me to evaluate it correctly at the time. Re-reading a bit over a year later, I'm finally able to step back, take off my development-editor hat, and enjoy the story as a reader.
One of the best things about this series is the character arcs, and in this book Pet is having second thoughts about her hard-won independence. It's not so easy to insist on being told things when the answers are more terrifying than the questions. Does she really want to know the truth and fight the battles, or would she prefer the safety of being Zero's pet, letting him take care of her, closing her eyes to her own calling, and giving over the custody of her conscience to someone she knows for certain doesn't fully understand her concerns, much as she loves him?
At the same time, Zero is giving Pet more answers than ever before, memories are resurfacing, and JinYeong is battling against a truly heroic level of romantic obliviousness on the part of Pet, to say nothing of Zero's sudden overprotectiveness. As for Athelas, he's behaving more suspiciously than ever.
With all the rich characterisation and compelling relationships you expect from this series, BETWEEN CASES may be something of a bridge to the thrilling, twisty final three books...but it's also a solid entry in its own right, with a satisfying plot and plenty of revelations and setup for what's to come.
"That's my emotional support vampire!" I said crankily. "Put him down!"