Dinah and her brothers are pretty sure they are rid of the Demon Headmaster once and for all. When the army start dismantling the biogenetic research centre Dinah contacts Professor Claudia Rowe, who is an expert on biology and genetics at the nearby university. With Dinah's help she saves some of the precious materials and they become friends. Then weird things start to happen. Libraries start closing and their books are taken away. Telephones stop working, and there is no internet access. People start talking like robots, even Claudia Rowe, and more and more of them seem to be wearing strange badges. It all adds up to one thing: the Demon Headmaster must be back.