Luna lives in a swamp created by several fallen trees that has been rising each year eating away at the land of their village. Luna’s Granny Tu can remember when the river was clear and the water was clean before the swamp. It is believed that at the deepest point in the swamp there lives a creature of dark magic who has created a poisonous slick of water. From that slick of water comes river sickness, a malady for which there is no cure. Three weeks to the day after drinking the water the sufferer dies. Luna’s younger sister Willow has come down with river sickness and Luna is determined to find a cure, even if it means battling the river creature herself. It will take great courage from Luna and the help of her friend Benny to save her sister.