Once again, Cathy receives a very unusual gift from her dad for her tenth birthday: an egg.

 

When a duckling comes out of the egg in the presence of her friend Margaux, he immediately recognizes her as his mother! But Margaux is not fit to handle a baby duck and her parents want to get rid of it. Both girls are resolute to save their palmiped friend and embark on a fantastic journey where they will learn a lot about self-discovery.