Heirs of the Sea, Henning S.

Everyone knows what to sacrifice the young mermaid for the sake of love. However, no one knows what the sea witch gave for her freedom and power over the underwater world. There were three: Aliyah, a beautiful young mermaid, who gave a voice in exchange for the prince's love. Her sister, a rune, ready to save Aliya at all costs. And Evi, a witch imprisoned in the sea prison.

In order to survive each of them to use the ancient magic of the depths. However, the sea is insidious, and the price may turn out to be exorbitantly high.