There was a rave review for this in one of my FB groups ... I'm surprised my library hold came in so quickly (it's new/popular). As I was in it, I was thinking "so, what was the rave about??"  I mean, it was fine, a little disjointed jumping between POVs, time shifts. A little "really?" just pushing the bounds of what could be considered realistic. The ending ... okay, I'll admit I got sucked in there. But still, maybe just 3*?  But when I looked to the Kindle copy and re-read portions (and almost felt like re-reading the whole thing), thought about what might come up for discussion in a book club setting, read a few reviews that brought out some good points ... bumping it up.

I was able to borrow both the audiobook and the kindle copy, I went primarily with the audio, but turned to the kindle a time or two, and afterward. No chronological chapters, just the listing of the changing POVs. This can make it really hard to shift between formats, or find your spot (no "I know I was at least to chapter 13") ...

The POVs shift between Rowan and Dominic (both 1st person/present tense). Orly's chapters were different, a 1st person, but really 2nd, speaking TO us/the reader (or someone else?) They reminded me a little of the "blog posts" in How The Penguins Saved Veronica (a few other similarities to that book too/the setting/penguins). Very intelligent and well spoken for such a young child. Then there are the Fen/Raff chapters, and one from Alex, which are 3rd person/present tense - these had a distanced feel, like a voice-over from an omniscient narrator. 

I struggled a bit to follow parts of the story. Rowan's chapters would jump around, still present tense, but in the past, no headers or anything to tell us when this was happening (but, she's healthy and off the island, so, before). There's lots of hints dropped, and foreshadowing (more obvious on a re-read than on the initial listen). SPOILERS 

I wasn't sure I bought how quickly Dom and Rowan fell into bed, especially with her body being as beat up as it was, her whole side stitched up. And the whole hidden Hank ...

No discussion questions included in the text, but a Google search found these, and they are good and really made me think and appreciate some of the complexities of the writing more ...
https://images.macmillan.com/folio-assets/rgg-guides/9781250827951RGG.pdf
One of the reviews by a GR friend/Barbara also made some good points. 

Salt ... I wish that wasn't the family's last name. I've only read the first of the Seven Sisters series, but even I can't help but think of Pa Salt. What's in a name? It distracted me ...

proFanity x 32 and some sex, not super explicit, but not closed door.