Guinevere Jones Book 3 - The Dark Side of Magic 
Based on the hit TV series, Guinevere Jones, these novels follow the fortunes of Gwen, who keeps seeing visions of the past. But when Merlin tries to tell her the truth, it's way too weird for Gwen to believe him! Book 2: Love and Other Magic, and Book 3, The Dark Side of Magic, by Felicity Pulman. Books 1 & 4 by Sophie Masson.'
When the Black Dog of Death and a demon headmaster threaten her friends, Gwen risks everything to help them. As she and Michael are drawn deeper into the dark side of magic she becomes increasingly isolated, and when she gives up her magic powers to please Josh, even Merlin can't protect her from the forces of evil gathering against her.
Published by:
Random House Australia, Level 3, 100 Pacific Highway, North Sydney, NSW 2060. Website: www.randomhouse.com.au