The successful writer Erich Eckberg lives with his wife Sigrid and their three children, the twins Knut and Michael and their daughter Gabriele, on the stately country estate “Sophienlund”. On the sons' 21st birthday, the day they came of age, Eckberg reveals a great family secret to his children: Knut and Michael are not his wife's children. Her real mother - with him as fathe...