In 1988, 13-year-old Lilly lies with her mother Rita, who escaped from East Germany 15 years earlier. Now Rita is dying of cancer, so her sister Lena, still living in the East, tries to get a visa to visit her, but her reason is not important enough, so she is only allowed to visit the West for one day: the day after Rita dies. At Rita's funeral, Lena and Lilly meet for the first time. Lena suddenly wonders who will look after Lilly now, because her dad died shortly after her birth, and the rest of the family lives in the East. Lilly is staying temporarily at a boarding school. After the day they spend together, Lena must take the train back into the East or be arrested. Before the train leaves the next day, Lilly escapes from school and implores her aunt to take her with her. Lena doesn't know what to do; getting a child into the East is impossible. The train leaves Hamburg and she must leave Lilly crying at the railway station. Shaken up in her feelings, Lena returns to her family in Jena, angry with herself and the system, because she knows she'd be imprisoned if she took Lilly with her. After her sister escaped in the West, Lena was already in prison for three years because she helped her. In Hamburg the youth office looks for foster parents for Lilly. Not knowing what to do, Lilly makes a plan to flee into the East. But this is not as easy as it seems. Together with her mother's friend, she travels to East Berlin, and from there on by train to Jena. In the evening, she arrives at Lena's flat for her cousin Till's birthday. After a little trouble she is warmly welcomed by Lena, but this isn't the end: she isn't allowed to stay there; she's a danger for the family. So Lena's husband refreshes his contacts with the underground, to find a way to let Lilly stay. Also, Lena's daughter Kathrin makes trouble because she can't stand Lilly and tries to get rid of her. Then Immigration shows up looking for Lilly.