Dunne has winter break. Of course, she longs for her best friend Ella Frida, who has a birthday coming up in the next few days. Dunne simply has to go to her in Norrköping! But no one has time to take her: Dunne's dad is visiting relatives in Italy, her grandmother has her bridge friends over, and grandfather's car is broken. Then grandmother makes a daring suggestion: Is Dunne brave enough to travel by train? All alone? - Absolutely! Rose Lagercrantz tells a truly thrilling story in the sixth book of the Dunne series about a train journey in a snowstorm that ends very differently than Dunne had imagined.