Rowan and the Keeper of the Crystal

When a mysterious messenger arrives in the valley of Rin, Rowan learns that his mother must travel to the seaside land of Maris. There she will choose a new Keeper of the Crystal to rule the strange, fish-like Maris people. But when his mother is poisoned, the responsibility for choosing a new Keeper of the Crystal falls to Rowan. In a desperate race to find the antidote for his mother, Rowan's only help comes from the three candidates for the position-one of whom is the likely poisoner!