Ethan, an author of children's books, travels to a coastal village rumored to be home to mermaids in search of inspiration for a new story. After an unexpected fall into the sea, he stumbles upon a mysterious pearl—one that grants him the ability to breathe underwater. Excited by his discovery, Ethan eagerly plans to use it as the basis for his next book.

But that night, the true owner of the pearl emerges from the depths. The mermaid forcefully claims what is his—and offers Ethan a deal he can’t refuse…