The Sea of Trolls is the first book in a trilogy that honestly should have been a one-shot novel. The other 2 books in the trilogy are not nearly as good as The Sea of Trolls.
The Sea of Trolls is highly recommended. It is an excellent stand-alone novel. The other 2 books in the series I would stay away from if you actually liked The Sea of Trolls.
So there is a kid that is the apprentice of what is pretty much a Bard. The book has a lot of elements of Norse Mythology in it. So the Bard has shit happen to him and the kid has shit happen to him. The kid ends up taken captive as a slave and then wows the people that caught him with his mad bars. So they give him a position on the ship and nix his slave status. More shit happens and eventually everything is all cool. Lots of really sweet mythological things end up being explored.
Not gonna spoil the book here for anyone that has not read it yet. But yeah. Discuss.