Title: The Night of the Solstice
Author: LJ Smith
Published: September 1993
Publisher: HarperCollins Publishers
When Claudia Hodges-Bradley meets a fox, she knows it will be an extraordinary day. Not just any fox, this vixen is the magical familiar of the sorceress Morgana Shee. For years Morgana has guarded the solitary gate between Earth and the Wildworld, a shimmering parallel universe where legends still live. She alone holds the secret of the mirrors that serve as the last passage to enchantment. But Morgana has been betrayed and imprisoned in Wildworld, and the fox is determined to recruit the Hodges-Bradley kids for the rescue mission.This sounds more middle grade-ish than YA. It might just be a little too high fantasy for me. Anyone?
Armed only with courage and determination, Alys, Charles, Janie and Claudia must save Morgana before the Winter Solstice when the evil sorcerer Cadal Forge plans to escape Wildworld and conquer Earth. And with December 21 only two weeks away, there is no time to lose? (from Amazon.com)