A simple, attractive success story of Mary Jo Milis, as she and her grandmother are faced with poverty and the possible loss of their home. Mary Jo, 15, by dint of much work and much courage, holds a job at the local veterinarian's and helps Grandma by bringing her boss home as a boarder. Not too Horatio Alger touch, and sound, young values throughout. Dr. Grant's romance with the wealthy Carol forms a romantic theme while Mary Joe's energetic relationships with her world and ""Beaver"", Dr. Grant's young brother, stay on a simpler level. Dogs and cats enough for any animal lover.