Emily Windsnap lived her entire life on a small yacht. But for some reason her mother, Mary Penelope, does everything possible to keep the girl away from the water. When Emily eventually gets into the pool, she makes a stunning discovery...

Emily learns more and more about herself and about the beautiful underwater world ruled by Neptune. She finds a friend and discovers the truth about the father she has never met. Having revealed a family secret, Emily is ready to do anything so that her parents can meet again. Her courage surprises and touches even Neptune himself.

This is a beautiful fairy tale, in which there is a place for the most amazing characters - the little mermaid Shauna and the clairvoyant fortune teller Millie, the lighthouse keeper Mr. Beeston and the mischief maker Mandy Rushton.