The Sunken Forest

The eighteen-year-old Mererid is the last water sorceress living in the Welsh principality of Gwelod. The gift of controlling the water element is both a blessing and a heavy burden, determining her fate. The lords will do anything to ensure that the sorcerers serve only them.
For several years, Mer has been hiding from the prince, who used her gift for evil. Now she only wants a safe, peaceful life away from rulers and wars that bring death and destruction.
But the prince's chief spy Renfro finds Mer and persuades her to help him overthrow the tyrant.