Like many others, I am a huge fan of the original Sevenwaters trilogy. I've re-read each of those first three books many times, loving the touching romances, the strong heroines, the atmosphere, the way the whole Sevenwaters family came to life--basically everything. I was even delighted with Heir to Sevenwaters on the first couple of reads, and while nothing else Marillier has written quite stands up to the original Sevenwaters trilogy, I've found several of her other books to be enjoyable and wonderfully romantic. So I'm disappointed with this book, although Marillier's writing has been headed this way for some time; I noticed re-reading Heir to Sevenwaters, and later with Heart's Blood, that there was something missing. Here though, it really comes to a head.
To start with the plot: Sibeal (the child seer from Child of the Prophecy and Heir to Sevenwaters) is now 16, and is visiting her family on the island of Inis Eala before taking her final vows as a druid. She meets a young man, and things progress exactly the way you think they do. That's part of the problem: that this book is so predictable. The leads and their relationship are very similar to previous leads and relationships. Sibeal even has a narrative voice virtually identical to that of her sister Clodagh in the previous book--although the two are supposed to be polar opposites. This book is narrated alternately by Sibeal and her love interest, Felix, and I'm not convinced this was a good choice; his voice isn't distinct either, and to be honest he doesn't sound much like a man.
Which brings me to another point: all the characters in this book are ridiculously sensitive. When strangers die in a shipwreck nearby, everyone speaks in hushed voices and loses their appetites for days; there's a constantly voiced concern about whether people are "ready" to talk about traumatic events; characters are forever telling each other how wonderful or brave they are, and showing open admiration for anyone who does anything remotely challenging. Wait a minute. We're talking about a warrior-based community in 9th century Ireland here. Few people in real life are anywhere near as sensitive or thoughtful as every single "good" character in this book. It didn't ring true to me at all. And this was before the inhabitants of Inis Eala decided to take an extremely perilous voyage to parts unknown to save three strangers--almost without discussion, because this seemed to them the obvious choice. Marillier's writing has always been idealized in at least some aspects, and I've enjoyed it, but here the selflessness was taken to such extremes that I didn't feel like I was reading about real people.
Add the problem that far too little is at stake in this book. Previous books featured serious threats to the main characters and everything they held dear. There's nothing of that sort here. Instead there's a random, voluntary escapade to save some strangers; but it's a one-off unrelated to anything in the larger series, and it never really feels dangerous despite its perils. Problems are quickly solved and the leads remain confident of their success throughout. The only real challenge Sibeal faces is the conflict between her goal to become a druid and her feelings for Felix, and even that is easily and predictably resolved. (Oh, and the insistence that no woman can possibly be happy without a husband and children and freely showing all her emotions has gotten gratuitous. It's one thing for many of the characters to believe it, but another when the author utterly changes the heroine to fit that mold and then calls it "growing up.") Stripped of genuine suspense or loss, but left with lots of recycled sentiments and metaphor-heavy speeches (is it really necessary for Sibeal to explain to all of her relatives individually that she loves Felix like a tree loves the sun, and so on? Maybe she could simply say she loves him, especially since she's meant to be reserved?), the book felt rather sterile.
I can see why the reviewers so far have liked the book: it's cool to see beloved characters again, and it entertains well enough. It's not terribly written, and I also liked the subplot dealing with the shipwrecked woman Svala, which was clever. Ultimately my reaction might be as much as result of my tastes changing as of the changes in her style. But at this point I would suggest to new readers that they read the original trilogy and leave it at that.