Facing the Demon Headmaster — Gillian Cross

The new club Purple is the place to go-if you can get in-and Ellie persuades Dinah and her friends to come along too. The man everyone wants to see is DJ Pardoman whose face keeps changing from Elvis to Madonna to Brad Pitt. His electronic mask is mesmerizing but no one knows who he really is.
When the kids visit his website they see there's an online competition-the person who finds out about him will be allowed to lift off the mask. Dinah thinks it's all weird but she's also curious. In her search she stumbles across something amazing-her real father might be alive after years of
thinking he was dead. Dinah must find out more. But she only realizes the truth of these strange coincidences too late. This time the Demon Headmaster is intent on ensuring that Dinah will not interfere with his plans.

Gillian Cross has won the Carnegie Medal, the Whitbread Children's Novel Award, and the Smarties Prize, and is a highly-acclaimed author. Sales of Gillian's books exceed one million copies.