I loved Whitfield's Benighted and was so excited to read her second book that I pre-ordered it from Amazon. Now I'm wishing I'd waited to get it from the library, or skipped it entirely.
The premise of the book is this: in an alternate-history version of medieval Europe, kings must retain the support of the "deepsmen" (merfolk), such that every country with access to the ocean is ruled by a half-blooded king. Being jealous of their power--in the form of the ability to communicate with the deepsmen, whose communication consists of dolphin-like sounds that "landsmen" (regular humans) can't produce--the royals have any non-royal half-blood child killed. But England is in trouble: the king is old, and the only heirs to the throne are a couple of teenage girls. Enter the protagonists: Henry, an unauthorized half-blooded child, and Anne, the younger of the two princesses.
A large part of my problem with this book is that I didn't buy the premise. Now, the idea of the deepsmen is fascinating. These aren't your mythical merfolk; Whitfield must have really thought about what such people would actually be like, and they're anything but romanticized. If you're looking for new ideas and something that hasn't been done before, you might find this book worth reading for this alone. But the way they're portrayed--with an intelligence level somewhere between that of a normal human and that of a dolphin, and primarily concerned with their own survival--I never bought into the idea that they were essential allies for anybody. And even supposing that they were, the idea that disabled kings (did I mention that the half-bloods can't walk, and at best hobble around with canes? It's painful to read about) could hold thrones all over Europe for hundreds of years merely because they can talk to the deepsmen is both ridiculous and unnecessary. That's what ambassadors are for.
Moving on to the story itself, though, we follow Henry as he's being secretly raised to be a king (having been conveniently discovered on the beach by someone who was willing to risk execution to keep him hidden) and Anne while she's... well, that's another problem. For the first half the book or so, Anne doesn't do much. At about 130 pages, I put the book down in disgust and left it for a month or so, but once I've bought something I hate to not finish it. It does get better in the second half, and one thing I can say for it is that both the plot and characters are original; since it's not something I've seen before, I didn't know how it was going to turn out, and that's always nice. It turned out to be a quick read, but with nothing memorable except the idea of the deepsmen; the prose and the character development are competent, but things become far easier for the protagonists than they should have been, and opportunities for action and excitement are continuously evaded. The dealing with the two major antagonists toward the end was unrealistic and silly. It can be rather difficult to sympathize with the protagonists as well: we're supposed to support Henry in his quest for the kingship, when he wants it only to avoid execution for his bloodline. He clearly has no aptitude for the position, even flat-out stating that doesn't care for or know anything about the people of England. (The author, who's British, seems to be counting on nationalistic sentiments here, since the other option is French. As an American, I thought the other option was much better.)
This isn't necessarily a terrible book. There are some good parts--the feral-child part of Henry's story, Anne's growth and learning how to take responsibility, and most of all the originality. Thematics are certainly present and may redeem the book in the eyes of more "literary" readers than I. Still, due to plotting and believability issues, I can't recommend it.