I first decided to read these books because they were by the same author who wrote one of my favorites, The House of Scorpion (more about that later). I was surprised at the complete change in these stories had from that first book. This series is full of Norse mythology that was way cool. Nancy Farmer, the author, is an expert researcher who has a nice way of putting factual information into a very readable story format.
All three of these books are full of humor, history, mythology, and adventure. The series as a whole is deceptively complex given the fact that readers encounter Vikings, trolls, dragons, elves, sea hags, overbearing fathers, and all sorts of other interesting stuff in the same book. As a bonus, just in case you are new to these characters or situations...Ms. Farmer includes appendices or glossaries at the end of every book to help fill in the details.
The series starts with the Sea of Trolls when eleven-year-old Jack, who had been happily apprenticing with The Bard, and Jack's five-year-old sister, Lucy, are captured and enslaved by the Northmen heading off to destinations unknown but where undoubtedly the Vikings will be pillaging. Though Jack's situation as a captive is nerve wracking, the author has a nice way of interjecting humor at times too:
" 'I know how exciting pillaging is,' the giant said fondly, ruffling Jack's hair. It felt like a blow. 'No matter how much you're tempted, just say no.'
" 'Just say no to pillaging. You got it?'
The story continues in The Land of Silver Apples where among other trials, Jack's sister Lucy is taken by Elves and he has to travel underground to their lands to get her back. What happens to Jack underground involves several great sacrifices and difficulties with the Elves whose immortality and lack of compassion make them cruel, vain, difficult to please and fickle.
In the final installment of the saga, The Island of the Blessed the apprentice bard Jack and his Viking companion Thorgil, come up against the vengeful spirit of a mermaid which leads to a journey taking them into the land of the fin folk and beyond.
Besides the engaging story line and relate-able characters, what I personally liked best about this series is the interesting way that conflict (or tolerance) of differing religions, cultures and customs is experienced-- where no one way of doing something or belief system is put down, and all have something to offer. Not to put too fine a point on it, but this is a great message...and an enjoyable way to hear it.