When eleven-year-old Gwen ventures into the forest beyond her castle home she comes across the magical island of Avalon and her life changes forever. The lady of the lake, Nineve, asks Gwen to embark on a quest to protect the enchanted island of Avalon from the evil sorceress Morgana Le Fay.
Morgana has imprisoned the eight Spell Sisters of Avalon throughout the kingdom and stolen their magical powers. It's up to Gwen, her best friend Flora and a very special horse named Moonlight to find the sisters and return them to Avalon before its magic is lost forever.
In their third adventure Gwen and Flora must find Isabella the Butterfly Sister. But with wolves under Morgana's magical control stalking them through the forest, will the girls be able to find Isabella and return her safely to Avalon?
Amber Castle has always loved fairy tales and the legends of Guinevere and King Arthur. She's also a keen horse rider, and when she tried archery for the first time a few years ago, she found it so much fun she now does it every week! Mary Hall was born in Essex. She studied architecture at Bath University and become an architect before turning her hand to children's book illustrating. Mary has worked on books and magazines and has now been illustrating for over 15 years.