Facing the Demon Headmaster

The Demon Headmaster is back! But what has he got to do with Purple? Purple seems like the most fantastic club ever--and the DJ's brilliant. But why does he wear an electronic mask, with a face that keeps changing? What is his real face like? The mystery deepens when Dinah stumbles across something amazing on the Internet... Can she and her friends move fast enough to defeat the Demon Headmaster's most threatening plan yet?