Quadehar the Sorcerer (Book of the Stars)

Imagine a lost isle, hidden behind magical doorways, caught between two worlds - the real world and an uncertain place of strange creatures and fantastical lands. Here, Robin Penmarch enjoys ordinary life, spending time with his friends and playing computer games whilst protected by extraordinary magic and brave knights in armour. But the dark forces of The Uncertain World are rising, and when Robin is unexpectedly chosen as apprentice to Quadehar the Sorcerer, he discovers the truth about himself and the threat to the Lost Isle. Soon Robin and his friends find themselves crossng over into The Uncertain World. There they face bandits, monsters and a shadowy enemy that will stop at nothing to capture the boy and his special powers.