After the death of her parents and her beloved instructor, Wind, Glynn devotes herself to the care of her sick twin sister, feeling her own life to be unimportant. One night, during a midnight swim, she is swept across the Void to the troubled watery world of Keltor, through a portal created to summon the mythical Unraveller. What is the mysterious connection between Glynn's world and Keltor? And why does the man who rescued her from the waves bear an eerie resemblance to Wind?