It's amazing! The Hyperbrain is a super intelligent computer that works by accessing the human brain. In the wrong hands, though, it could spell disaster. The new Controller at the Artificial Intelligence Unit seems horribly familiar but Dinah and her friends know that the Demon Headmaster has been defeated. Hasn't he? Great fun and just a little bit frightening, Gillian Cross's Demon Headmaster books still hold readers under their hypnotic spell. Fast-paced and full of adventure, they're impossible to resist!