Here's a brief review of The Sea of Trolls. Contains minor spoilers.
Nancy Farmer’s The Sea of Trolls is an entertaining children’s fantasy and adventure novel set in the early Middle Ages, at a time when Vikings still roamed the North seas. Although the novel is fairly engaging, it is basically a typical juvenile adventure story that did not break any new grounds like Farmer’s previous novel, The House of the Scorpion. Jack is an eleven-year-old son of a farmer living on the British isles with his parents and his younger sister, Lucy. Although he possesses no special gifts as far as anyone can tell, he is chosen as the apprentice by the Bard of the village, who, as it turns out, has a secret past and a vengeful enemy in the form of a half-troll queen of the Northmen. Not long afterwards, the village is attacked by the Berserkers sent by the half-troll queen, the Bard becomes a witless idiot, and both Jack and Lucy are kidnapped. In order to win Lucy’s freedom, Jack is sent to the kingdom of the trolls in the far north to complete a mission, traveling in the company of the Berserkers, including a blond Shield Maiden named Thorgil. Thus begins a wild adventure full of action and danger. Farmer integrated many Norse legends, as well as pieces of actual history, to weave an imaginary tale. This is a novel appropriate for younger readers and all those who enjoy children’s fantasy.