Maria Berger (Christine Neubauer) works as an adviser in a lawyer's office in Thailand which specializes in divorce. Since her own marriage ended in divorce she is herself fundamentally opposed to marriage; she simply doesn't believe in the myth of everlasting love - although at the same time she finds brief affairs basically unfulfilling. Her younger half-sister Clara (Suzan Anbeh) and her father Willi (Charles Brauer) run a holiday resort in Rayong, and now Clara and announces that she wants to marry a Thai musician. Although she is actually opposed to the idea, Maria arranges the wedding in grand style. When she comes to view the location for the party she encounters Martin Wagner (Hardy Krüger jr.). Maria quickly comes to feel close to this attractive man, and they enjoy a time of great tenderness on his junk. But the following morning Martin wakes up alone; Maria has secretly slipped away during the night.
During Clara’s wedding celebration the two sisters are stunned to find that their mother has turned up after all: Elaine (Ruth Maria Kubitschek) had told them she would be unable to attend. When she makes an entrance like a primadonna she naturally attracts everybody's attention, which annoys Maria; after all, surely the bride should be the focal point on her own wedding day. Suddenly Clara collapses in agony, and when she is examined in hospital the family find themselves confronted with a terrible diagnosis: a Clara has an inoperable brain tumor! When she discusses this with the senior doctor Maria discovers to her amazement that Martin is in fact a respected radiologist with extensive connections. She immediately tracks him down and begs him to help Clara - but he refuses. He explains that he had to watch his own wife die of cancer, which made him feel stretched to the limit of his personal and professional abilities. Since then he has never practiced medicine. But Maria is determined to find a way to save her half-sister’s life. At first it doesn't even occur to her that this may also represent a chance for her to find happiness in her own life.