Was very engrossed with the beginning of the book and its developing mysteries, but the further I got in the more tropes started to wear thin and some unnecessary plot twists/points came out of nowhere. 

All my thoughts pretty much contain spoilers so beware.

Opaline's brother turning out to be her father had no narrative significance? Other than painting him as more of a bad person? Which, yeah, I kind of already got that due to his abusive ways and throwing her into a mental asylum to get the coveted manuscript. Really didn't need more spelling out and it just doesn't mean anything.

Also.....why did her falling in love with a Nazi soldier, an Austrian P.O.W. to be exact, have to happen? Why did she even need to be married at all to a lump of nothing character with no personality? And why a NAZI of all things? I know the character was forced into service but again, WHY? What does that bring to the story other than our main heroine who we've been rooting for his whole time falling in love and marrying a Nazi? Just weird.

The ending is pretty baffling. I didn't really understand what exactly happened and I don't think the book can chalk it up to the nature of magical realism.