As the daughter of the director of the Leipzig Zoo, Susanne Mertens grew up with the animals that live there. Although she found her dream job as a veterinarian at the zoo, she temporarily gave up her profession after her marriage to Klaus and the birth of their son Jonas. When dr. Vogel offers her an assistantship as a veterinarian, Susanne is enthusiastic - Klaus less so. Only when Charlotte, Susanne's mother, supports her daughter, does he give in. Not only does Susanne face professional challenges in her day-to-day work, but she is at odds with Dr. Fährmann, the zoo's new director.