Effective ending to the trilogy that answers most of the questions but leaves some doors open.
The story is solid and the world building interesting, specially the mythology that gets, again, more importance.
If the mystery is quite well built, the romance seems forced

Spoiler

as a way to introduce the villain that otherwise would feel as distant as in the second book and would have felt a bit like cheating.

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In the end, I get a sense of a very ancient valley where women were much more important than in other parts of the country, where traditions were followed and still are. I get a sense of a well built mystery with a few threads that need a bit more trimming. And I get a sense that the author could move Amaia to the FBI for a new mystery concerning Dupree. But that would be another story.