Dinah Glass, an intelligent and observant girl, is fostered by the Hunter family and begins attending their school. She quickly notices that the students behave oddly: they're unnaturally well-behaved and eerily enthusiastic about the headmaster. That’s because he uses hypnosis to control them. A small group of children immune to his powers—known as SPLAT (Society for the Protection of our Lives Against Them)—begin to uncover his sinister plan: to hypnotize the entire country via a national school quiz broadcast. Together, with Dinah's courage and smarts, they work to expose and stop his evil scheme.