I would say that I recommend this to fans of Emily Wilde's Encyclopaedia of Faeries and fans of WWII and WWI epistolary novels. The tone is very similar to books like The Guernsey Literary and Potato Peel Pie Society and Last Christmas in Paris, and the setting is a sort of steampunk water world where there seems to be a big social emphasis on scholarly pursuits such as natural science and innovation. I found the setting and tone very charming, and I was compelled along by the mystery as well. The audiobook did a good job of providing multiple narrators to keep it clear who was speaking. I enjoyed the "present day" perspectives of two people who were trying to determine what had happened to their respective siblings who had perished/disappeared sometime in the previous year, and it was interesting to follow their reactions to the letters exchanged between the missing couple as they fell in love before whatever happened to them. I related more than I expected to E's mental health struggles. Towards the end I sort of lost track of what was going on and I honestly couldn't tell you what happened. The book also ends

with the big mystery unresolved. Coupled with my general confusion, the lack of a clear ending made for an ultimately unsatisfying read. It does appear this may be the first book in a series, but I didn't know that while reading.

If I were going based on the ending I might give it a 3, but I'll stick with 4 because I think I'm partially to blame for not paying enough attention while multitasking with the audiobook on and I did really enjoy the earlier parts of the story.