I thought I would adore this series. I love historical fiction; I love middle grade/YA books; I love Norse mythology; I love books about the British Isles and about folklore, so I doubly love books about British folklore. And this series had it all. I thought that this one would be one of those series that I would check out from the library and love so much that I'd run to the bookstore and buy my own copies. And then I read the trilogy and it was . . . nice. It was fun. But it wasn't great.

Each book in the series has a unique set of strengths and weaknesses. In this first book, the plot was a bit rambling; the actual conflict, the part that you would focus on if you were explaining to someone what the book was about, isn't even mentioned until halfway through the book. Rambling epic journeys work, but only when we always know the end goal. The writing style was a bit uneven; generally it was what you'd expect for an 8th century epic journey, but occasionally a very modern-sounding line or word would pop up and sound thoroughly anachronistic--for example, the characters all use what are supposed to sound like period curses ("By Thor's hammer!") but at one point a character's curse is edited out with a string of #!@& like in an old cartoon. It's an attempt at a joke but it feels out of place. The use of the nursery rhyme "Jack and Jill," though Farmer does have a historical basis for its conclusion, is thoroughly jarring.

The characterization in Sea of Trolls is hit-and-miss as well. Jack is fairly likable; he feels realistic and you believe in his motivations, even if he spends a great deal of time waiting for things to happen to him. The Bard would be the coolest teacher ever. Many of the less-important Vikings are entertaining, and the Viking named Rune is quite sympathetic and interesting. But secondary protagonist Thorgil is so ill-tempered for so long, with absolutely no signs of humanity, that when the author wants you to start feeling bad for her, it's hard to actually dredge up any sympathy. And her turn to friendliness is quite sudden and unfounded. I found certain other characters, such as Jack's father and sister, almost unbearably irritating.

And the Vikings in general posed a problem for the author. Jack spends most of the book in their company, and he has exciting adventures and becomes a better bard for it, so you become attached to those characters and their world. The fact remains, though, that they're murderers and thieves and slave traders, and the reader, like Jack, can't really decide whether or not we're supposed to like them. And maybe that was Farmer's point--that the lines between good and evil are blurred in real life, and that in a world as harsh as the Northmen's, where pillaging is the only way to survive, someone can be kind and funny and a devoted family man but also a cold-blooded killer--but it never feels like that's what she's trying to get at. It just feels muddled, like Farmer could never make up her mind about Vikings either.

For all that, though, there are a great number of excellent aspects of this book. Most of these have to do with the huge amount of research Farmer must have done. The best historical fiction books, in my opinion, pack in period detail but do it so deftly that by the time you're done, you're well informed on the time period but you don't feel like you sat through a history lesson. Sea of Trolls excels at this. Saxon England and Viking Norway are both recreated with astonishing detail that manages to avoid bogging down the story. History classes teach you the dates and the events, but the book takes you into people's homes, into the everyday lives of farmers and sailors and Vikings and kings. No less detailed is the description of the culture and the mythology. The book falters slightly where Farmer tries to reconcile all different religions and create a world where all belief systems are equally true, because it just doesn't work that well in her narrative, but other than that the mythology is fascinating. The beliefs of early Christians and Irish bards and Vikings are all described in detail, with bits of myths and legends woven in (Beowulf, especially, plays a huge part in the story). The focus, at least in this first book, is on Norse beliefs, and it's an excellent primer on Norse gods and the deeply Viking belief in fate and in the importance of achieving fame and dying heroically. That amount of historic and folkloric detail pushes this book up to four stars for me.