In the opulent yet treacherous court of King Louis XIV, the Sun King Pierce Brosnan is consumed by a dark quest for immortality. His ruthless plan involves capturing a mythical mermaid, whose life force holds the key to eternal life. This grand adventure takes an unexpected turn with the arrival of his long-hidden, strong-willed daughter, Marie-Josèphe Kaya Scodelario, who is unaware of her royal lineage. As she discovers the king’s monstrous scheme, Marie-Josèphe finds herself drawn to the captive creature and forms a forbidden bond that challenges her father’s authority and the very future of the kingdom. With the king’s loyal captain Benjamin Walker caught between duty and conscience, and the mysterious presence of a Chinese courtesan Fan Bingbing adding to the intrigue, a dangerous conflict erupts. This sweeping family adventure, directed by Sean McNamara, blends historical grandeur with enchanting fantasy, creating a tale where one young woman’s courage must defy a king’s obsession to protect a magical secret.