The Sea of Trolls by Nancy Farmer

This fantasy is based on Norse mythology, and I gave it a rating of five out of five. The story begins like The Last Apprentice, then turns into a little Vampirates, and then goes off on its own, distinct tale. Jack and Lucy are kidnapped by berserkers, and they sail away to the berserkers country. Think of the berserkers as werewolves on steroids! Jack was being trained as an apprentice bard before his capture, and he is able to summon some powers of the Earth. As an apprentice, this magic didn't always work as planned. Olaf, the head berserker, presents Lucy to his queen, and Jack performs a spell that makes the queen quite ugly. Jack is sent on a quest to find magic that will return the queen's beauty, but Lucy will be sacrificed to the gods if he doesn't get back in time.

Many of the characters come from Norse mythology: the god Odin, trolls, and even the berserkers. Some of the events in the novel refer to actual events in Norse history. Although I've read similar plots in other books, I enjoyed this author's twists as mythology was woven in. The use of magic isn't overdone, and the plot has much symbolism with deeper meaning. The description makes reference to the life force in the Earth and the balance of life on the planet. Good cannot exist without evil. The life force does not respond well to anger. The book makes you think.