Ten-year-old Siri and her little sister Miki live with their elderly father in an Arctic archipelago. One day, while they are out gathering snowberries, Miki is abducted by Captain Whitehead.

Everyone knows the story about Captain Whitehead, a pirate with hair white as snow and heart as empty as an ice cave. All he wants is children, the smaller the better. They say Whitehead has a diamond mine, a great chasm in the earth. To be taken to that mine is the worst thing that can happen to a child.

To prevent her father from risking his life to find Miki, Siri sets out to find her sister by herself. In Siri's adventure on the seas she will encounter wolves, sailors, mermaids, profound evil, and true humanity. The Ice Sea Pirates is a classic children's adventure and a humane story of sisterhood, friendship, and courage.