Susanne Mertens, the daughter of the Leipzig zoo director, grew up with the animals who live there. She found her dream job as a zoo veterinarian, but gave up the profession following her marriage to Klaus Mertens and the birth of her son Jonas. When zoo veterinarian Dr. Vogel offers her the position of assistant zoo veterinarian, she is excited - Klaus less so. Once Susannes mother, Charlotte, lends her support, he admits defeat. Her daily life presents not only work challenges, but she also continuously bumps heads with Dr. Fährmann, the new zoo director. In her family life, she painfully discovers that she can depend on her husband less and less. One day, she meets Christoph Lentz, the father of Jonas' friend, Rebecca. The likable Pediatrician turns into a well-informed counselor and, additionally, is always there when things get dicey.