Luna Nimue believes she is an ordinary ten-year-old girl. However, whilst struggling to fit in at Abbey Claire, a convent on the Irish coast, she discovers she is a witch. Using magic to travel through time and her newly-discovered shape-shifting abilities as a tengu; a mythical winged dog, she explores and develops her magical powers. At the same time, she yearns to speak with the moon, for which she has a great affinity, and is curious to learn the fate of her abducted parents who were taken when she was very small.