"The Great Brain Series" is a collection of children's novels written by John D. Fitzgerald. The series follows the adventures of a young boy named Tom Fitzgerald and his clever older brother, The Great Brain, who uses his intelligence to solve problems and outsmart others in their small town of Hollister, Utah during the early 1900s. The books are known for their humor and relatable themes, such as friendship, family, and growing up. Each story features Tom and The Great Brain navigating various challenges, showcasing the importance of creativity and resourcefulness in everyday life.