Gwenlyn Bennet has lived peacefully as an honorary member of the notorious Summers coven for ten years, but she's never known a blood relative until she wakes up with the ghost of her twin sister hovering above her bed. When the coven falls mysteriously ill, Gwenlyn embarks on a quest for a cure with the dubious help of her dead sister, but can the duo accomplish their task before the witches run out of time?