To be the first girl accepted into Santa school, twelve-year-old Lucia must find a cure for a mystery illness caused by the devilish Krampus.

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 be started for this year’s present production, Lucia’s best friend, the reindeer herder 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.

At Santa Claus School, the principal has called a meeting. Lucia, her parents Julius and Claudia and everyone else at school are excited. But the tension is replaced by a shock when the headmaster cancels Christmas. He seems confused, and it soon becomes clear that he is trapped in a Christmas trauma from his younger days as Santa Claus. Lucia sets out to find out what has happened and with the help of the younger student Elias and a magical time machine, she travels back in time in the hope of saving Christmas.