Charlie is a dog environmental investigator. On one of Charlie's many walks near a creek, he runs across one of his friends feeling sick. Charlie is really concerned that the source of his friend's illness is a potential threat to animals and humans. Follow along with Charlie as he meets with several of his friends that help guide him during his hunt to find the source of the hazardous pollutant. Also, learn about Charlie's featured friend, Nutria and how to help protect the environment.