The story takes place during the weeks before Christmas, in the small mining town of fictitious Granhyttan in Bergslagen, Sweden. One day a suspicious couple, Signe and Orvar, arrives in the small town and retires in an abandoned hut. Nobody knows what they up to; but strange things starts to happen as Staffan finds a gold nugget while playing in a disused mine at the Krakberget Mountain during a skiing trip with his schoolmates. Staffan believes the nugget is a part of Skarp-Erik's gold, as his grandpa had told exciting stories about. The news about the gold discovery spread quickly and Staffan and his friends are soon pursued by curious schoolmates, school staff and also the mysterious strangers. All this happens as the students are rehearsing for the nativity play before Christmas break.