The best con man in the Midwest is only ten years old. Tom, a.k.a., the Great Brain, is a silver-tongued genius with a knack for turning a profit. When the Jenkins boys get lost in Skeleton Cave, the Great Brain saves the day. Whether it's saving the kids at school, or helping out Peg-leg Andy, or Basil, the new kid at school, the Great Brain always manages to come out on top-and line his pockets in the process.