Katrin is a single mother of twins. When they find out that they owe their existence to a sperm donation, they persuade their mother to find their biological father.
| Actor | Role |
|---|---|
 Anica DobraKatrin Brand | Katrin Brand |
 Richy MüllerFrank Kolakowski | Frank Kolakowski |
 Katharina UrsinusLuisa Brand | Luisa Brand |
 Kai Ivo BaulitzMartin Brand | Martin Brand |
 Hans Peter HallwachsProf. Dr. Felix Gottwald | Prof. Dr. Felix Gottwald |
 Roswitha SchreinerGudrun Neubert | Gudrun Neubert |
 Christian GoebelDr. Thorsten Fischer | Dr. Thorsten Fischer |
 Caroline RedlSonja Böhmer | Sonja Böhmer |