Circle of three, book 07: Blue MoonIsobel Bird2001

Ancient moon, O ageless traveler, sailing on the sea of stars, as once more you come to fullness, turn your shining face to ours. The second full moon of the month—the blue moon—is a time when powers are heightened, with unpredictable results. When Annie attempts the channeling practice called aspecting, she changes into someone Cooper and Kate hardly recognize. Can their combined strength restore Annie's spirit?

Titre original : Circle of three, book 07: Blue Moon (2001)