Mysterious Fathoms Below

AU of 3x6. To save Ariel, Snow sacrifices herself and remains a mermaid. Instead of killing her, Regina steals Snow's voice and leaves her to wander the seas alone in revenge. But when she saves Charming from drowning in his attempted escape from King George, she confesses she lied about not loving him. He is determined to be with her, even if he has to become like her. Mermaid AU.