Vendetta (The Mermaid Chronicles book 5)

An ancient enemy threatens Atlantis…

For twelve years, Gal has nursed a burning desire for revenge. As the anniversary of his mother's death approaches, he leaves Atlantis, determined to track down Zale, the ruthless shark shapeshifter who robbed his mother’s life. But as he sets sail on his dangerous quest, he discovers his two closest friends have stowed away on his vessel. It’s too late to turn back now.