They share an ability for magic ... magic that comes with a challenging side effect: their bodies age and de-age with the phases of the moon.
Before Raven can learn anything about moon magic from her Nan, she is kidnapped by Cerridwen, Celtic Goddess of the Moon, who places a curse on Raven's voice. With only the help of a reluctant (and often annoying) Cait Sidhe, and an unreliable Dark Horse, Raven is cast adrift in the unfamiliar world of Tír na nÓg, relentlessly stalked by the Morrigan, Goddess of Death.
If she is to return home, Raven must somehow recover her voice and discover her innate talent for music and magic ... a nearly insurmountable task that would be a whole lot easier if she did not also have to fight off far-too-many nightmarish creatures, send a Chinese dragon back to his own dimension, and rescue yet another goddess from an ill-conceived marriage ...