The two twelve-year-old girls Charlotte Palfy and Louise Kröger meet on a language trip to Scotland and discover that they are twins who were separated shortly after birth. Charlotte, the daughter of a music hall composer, is cool, self-confident and cheeky, dresses accordingly and listens to techno music. Louise, who grew up with her mother, an advertising executive, wears more "old-fashioned" clothes, is shy and reserved, but conscientious and orderly. Determined to play fate, the two swap roles - at the end of the journey, Louise travels as Charlie to her father, who works as a composer in Berlin-Kreuzberg, while Charlie travels as Louise to her mother in Hamburg, where she works in an advertising agency. The girls realize that getting their parents back together is not as easy as they thought.
