To end the curse they must face the truth.
When Allie wakes up alone in an emergency room in Hawaii, she faces difficult questions. A boat owner found her half-conscious, naked and alone at a deserted dock. Where is her ID? What is the strange disease that threatens to kill her? Does she have a family?
Meanwhile, thousands of miles away in Arizona, her twin sister, Alysa, lives. Alysa struggles to rebuild her life after being in a coma for years. Both sense the other twin needs help but neither knows how to answer the call...or if they are deluding themselves.
When they meet, it sets off a cataclysmic reaction. In this riveting series conclusion, Allie and Alysa must face the creature that has stalked them since birth. Succeed and they might live lives fit for mermaid queens-fail and all they know will drown in the deepest darkness.