Morgain's Revenge (Grail Quest #2)
When Gerard, Newt, and Ailis broke the sleeping spell the king's half-sister, Morgain, had placed on Camelot, the sorceress was weakened but not defeated- she knew she had to strike again, soon, before she lost all credibility as a witch. Her next move is even bolder than her first- she transports herself into the halls of Camelot and steals Ailis, newly promoted serving girl with a witch's abilities, away to Orkney to train her in magic. All hope might be lost for Ailis were it not for the fact that Gerard, rounding a corner at the exact right moment, saw her taken, and now it falls to Newt and him to steal her back- but they aren't counting on the fact that Ailis might not want to come home.
Years ago, I read the first book in this series, The Camelot Spell, for two reasons, the first being that I love Arthurian mythology and the second being that I was looking for a book that painted Morgan le Fay as a proper villain, which this series certainly did at first. In this book, though, we start to see a bit of Morgain's sympathetic side, which is, in many ways, more accessable to a reader born well after women's lib. It used to frustrate me that so many authors insisted on painting Morgain as one of the good guys, but now I'm not so sure.
At any rate, I would strongly recommend this book as an introduction to Arthurian mythology- it really doesn't delve that far below the surface, but oh well.