Miriam Maertens grows up sheltered and without a care in the world, but the older she gets, the worse she feels. Then she receives a shocking diagnosis: cystic fibrosis. She promises her mother Christa that she will not die, and decides early on to lead a double life. Miriam lives her life as if she were healthy, keeping her illness a secret. When her father Peter reads in the newspaper about two doctors in Munich who have developed a new method for treating cystic fibrosis, Miriam meets people who can help her for the first time since her diagnosis.