Facing the Demon Headmaster by Gillian Cross
There's a new craze sweeping across the country - the mysterious DJ Peterman and his Purple club. Everyone wants to be a part of it - nobody wants to be left out. But when a competition is launched to find the real DJ Peterman, Dinah and her friends become suspicious. Could the DJ be their old enemy, the Demon Headmaster, in disguise? A fast-moving story with a series of surprising twists.