The curtain rises on a timeless tale, narrated by the captivating Julie Andrews, as we delve into the compelling journey of Marie-Josephe, portrayed by Kaya Scodelario. This spirited young woman has spent her life within the rigid confines of a convent, often pushing against the stern authority of the demanding Abbess, played by Rachel Griffiths.
Simultaneously, King Louis XIV, depicted by Pierce Brosnan, stands on the verge of addressing his subjects when chaos strikes—an assassin’s bullet narrowly misses him. In the wake of this attack, Louis becomes obsessed with his own mortality. Seeking a way out of his fears, he approaches Dr. Labarthe, skillfully performed by Pablo Schreiber, who entices him with tales of a mystical underwater creature, the Mermaid, believed to hold the power of immortality.
Louis assembles a crew led by Captain Yves De La Croix, portrayed by Benjamin Walker, to capture this elusive Mermaid and exploit her powers. Their perilous expedition leads them deep into the ocean's embrace, where they encounter the creature's mate, who valiantly defends her beloved but ultimately returns to the depths.
As the obsession with the Mermaid's powers grows, Louis orders Dr. Labarthe to retrieve a vital organ from her. Meanwhile, Father Francoise La Chaise, played by William Hurt, becomes increasingly disturbed by this amoral directive and seeks to intervene.
La Chaise devises a clever scheme to summon Marie-Josephe to the opulent court of Versailles, tricking her into believing she’s been invited to perform. Upon her arrival, she finds herself out of place among the elite, though she forms a bond with the compassionate servant, Magali, played by Crystal Clarke, as she grapples with her new surroundings.
The following day, Louis consults Jean-Michel Lintillac, depicted by Ben Lloyd-Hughes, whose wealth and impending title captivate the king’s interest. Meanwhile, Marie-Josephe, enchanted by the new world around her, is drawn to Yves. Their fates intertwine unexpectedly when Louis’s arrival sends her crashing into a fountain, leading her to encounter her father for the first time—though he remains distant.
As chaos unfolds, Marie-Josephe discovers her latent musical talent, which becomes the bedrock of her emotional journey. Touched by the Mermaid's plight, she dedicates herself to her music, using it to process the whirlpool of emotions surrounding her.
One intense evening, she stumbles upon the Mermaid held captive by Louis's men. Driven by compassion, she picks up her violin, and together they create a haunting melody that resonates throughout the chamber, blending the realms of music and magic.
As preparations for an extravagant ball commence, Marie-Josephe feels the weight of Louis's gaze, sensing an unexpected connection with the enigmatic king. Their dance beneath the stars reveals glimpses of his life, revealing the tender sentiment wrapped in loss and longing.
However, beneath the glamour of court life, tensions surface, especially as Lintillac is honored and Yves's recounting of their ambitious quest brings the room to an uneasy silence. Amidst this social veneer, Marie-Josephe's bond with the Mermaid deepens, leading her to moments of self-discovery near the water's edge.
But fate changes tides when a riding accident leaves Marie-Josephe with a serious injury. As Dr. Labarthe deliberates on grim options, the Mermaid appears as if summoned by destiny, healing her with a gentle touch. Marie-Josephe’s initial delight turns to dismay as she learns of Louis's ulterior motives for the capture of the Mermaid, stirring conflict in her heart.
As Louis seeks to control Marie-Josephe's future by orchestrating a marriage with Lintillac, despair overtakes her. In a gripping confrontation, she refuses to comply, leading her to make a desperate promise to save the Mermaid—one that Louis dismisses heartlessly.
Amidst wedding preparations, La Chaise and Yves unite to rescue the Mermaid, fighting against Labarthe's men in a desperate bid for freedom. Tragedy strikes when Yves is wounded, yet his loyalty drives him to help Marie-Josephe in her quest for liberation.
In a climactic showdown, Marie-Josephe defies Louis’s authority, confronting him and forcing a harrowing choice. As she plunges into the depths, the Mermaid intervenes, weaving a tale of survival as they escape the chaos together, with Yves at their side.
As the dust settles, the bond between Marie-Josephe and the Mermaid shines brightly, while Louis is left grappling with the tumult caused by his ambitions. With newfound resolve, Marie-Josephe and Yves embark on a daring adventure to seek the enchanted city of Atlantis, where they hope to unearth the secrets hidden beneath the waves, including a quest for understanding and connection with the Mermaid they both cherish. Through breathtaking landscapes and haunting melodies, they embark on a journey that will forever alter their destinies.
