Calpurnia loves nature and dreams of becoming a researcher. She has learned to identify plants and use scientific instruments from her grandfather. Together with her younger brother Travis, she cares for needy animals. An armadillo, a raccoon, and a puppy find a temporary home with her. Callie feeds and examines the animals, reads up on Darwin, and deepens her knowledge of natural history. When a veterinarian moves to town, it becomes clear that she is the perfect assistant for him. However, being a veterinarian is a profession for boys, and Callie is the only girl in her family. This charming sequel follows Calpurnia's (r)evolutionary discoveries.