Way up north in Greenland lives 12-year-old Lucia with her mother and her father, who is best known as Father Christmas. Lucia is the first girl ever in Santa class at the international Christmas School. On the day that the present machine is supposed to start this year's present production, Lucia's best friend, Oscar, is accused of stealing King Winter's magical crystal that fuels the present machine. Claudia, Lucia's mother who has long been wary of the crude Oscar, tries to prevent Lucia from ruining her future career by defending the seemingly guilty boy. But Lucia is determined to fight injustice and escapes with Oscar to prove his innocence by finding the real thief. Soon they are facing the secret brotherhood of The Grey Brethren, who have sworn to destroy the crystal and end Christmas for good. Lucia realizes that there is more at stake than she thought. Lucia and Oscar have to fight the brotherhood for the crystal all the way into the dangerous Eternal Storm to save Oscar, Christmas, and King Winter. Claudia realizes that her prejudice and ambitions for Lucia have clouded her judgment; Justice and friendship are more important than career and prestige.