John Dennis Fitzgerald

In the absence of his older brother, the Great Brain, J.D. finds that his own little brain can accomplish feats on a somewhat lesser scale.

The exploits of the Great Brain of Adenville, Utah, are described by his younger brother, frequently the victim of the Great Brain's schemes for gaining prestige or money.

The Great Brain faces the challenge of life at a strict Catholic boarding school with daring exploits and money-making schemes.