As the daughter of a shunned merman king stripped of his ocean magic, eighteen-year-old Luna ventures to the shores of Southern California for a life on land. She strives to find love and her long lost human relatives in hopes of establishing a human identity to help the mermaid colonies in the sea flourish. All her dreams seem to be within reach after a local beach cleanup draws Luna to handsome Ryan Reyes, a free diver in search of adventure, who loves the ocean as much as she does. But after both the land and the sea test Luna’s new relationship with Ryan, Luna discovers she’s not the only one with a secret—and Ryan’s threatens her existence on land. To escape Ryan’s treacherous past and create a future with her potential mate, Luna must learn to navigate the dangerous surface. If she can’t, her dream of living on land will wash away, forcing her back into the ocean.

Luna loves everything about the human holidays until her friends drag her to a ball that falls on the one night her mermaid heart can’t understand: Halloween. On a holiday made to find fun in fear, Luna wants to stay far away from the festivities, especially after her best friend picks her out a costume in her least favorite color. But Luna wants to fit in on land, and if facing monsters while wearing a pair of fangs assures it, Luna’s willing to try for her pod...and the promised mountain of candy that awaits. As the night reveals the true magic of Halloween, Luna meets a creature of the night that may or may not be real. Determined not to let a mysterious man stalking her jeopardize her fun with Ryan and her friends, Luna summons her pirate princess mermaid courage to face him. She’ll do anything to show this man, who fits perfectly in this night of horrors, that nothing will stop her from finding fun—even if it means the possibility of revealing the merpeople secret to the world.

The one thing Luna wants for the holiday season is to take Ryan to her home colony of Pearlestria to celebrate their first Winter Solstice together. But when the chief mate of her pirate crew gives her a surprise gift that requires more work than she bargained for, Luna is forced to change plans and take Ryan to shore instead. With only days until the celebration, Luna must summon some holiday magic and figure out how to turn the world’s worst present into something great for the seas. If she can’t, she will miss her favorite holiday and the chance to surprise Ryan with the gift his merman heart desires, ultimately losing her Winter Solstice cheer.