The film opens like a fairy tale with the Narrator talking about a young woman
named Marie-Josephe who was born and raised in a convent
She is a rebellious free spirit who often causes trouble for the nuns but mainly the Abbess
In France, her father King Louis XIV is preparing to give a speech to the French citizens
but an assassin fires his weapon at Louis
He is hit but unharmed as the man is apprehended
Fearing for his own mortality Louis is told by Dr. Labarthe
that there is a special underwater creature,
who possesses magical powers that can grant him immortality
the king Louis sends for a group of fisherman led by Captain Yves
They encounter the creature a Mermaid and proceed to capture her with a net
Her mate is also caught and attempts to fight off the fishermen,
but the captain Yves simply lets him go back into the ocean before heading back to France
Labarthe tells Louis that the procedure to make him immortal is accomplished during an eclipse,
and involves cutting out the Mermaid’s organ
The only one against this is Father Francoise La Chaise
Per the King’s request La Chaise sends a message to the convent where Marie is living,
and the Abbess is eager to get rid of her
La Chaise travels to the convent to bring the girl back with a crew
giving her the impression that she is traveling to play music in Versailles
Marie arrives there and is amazed by how beautiful the city looks
and She befriends a servant named Magali
but everyone else who doesn’t know she is the King’s daughter
looks upon her as a common outsider
The following morning Louis meets with Jean-Michel Lintillac son of a wealthy baron
Lintillac tells Louis that his father is gravely ill and ready to pass on
Louis discusses with La Chaise that Lintillac stands to inherit a fortune
and passing down his father’s title would benefit everyone
While out for a stroll with Magali
Marie notices others staring at her, They go to a fountain, where she sees
Yves for the first time and is smitten
When Louis and his men arrive, Marie loses balance and falls into the fountain
Lintillac pulls her out and she meets her father for the first time,
though he still doesn’t tell her his relation to her
In the meantime, Marie is set to practice music since it is one of her skills
and The men bring the Mermaid into a chamber beneath the castle
Louis learns that she is despondent and gloomy after being separated from her mate
and he orders the men to get her well so that the procedure may go through without a hitch
Later, as Marie tries to practice in her room
she senses a vibration against her harp and follows the noise she hears
It leads her to the chamber where the Mermaid is being kept
she meets the Mermaid and is stunned by her
Yves comes by to catch her
but Marie says that the Mermaid is making some kind of musical noise
which she syncs up with her violin playing
The next day, Marie plays music with the royal troupe before Magali helps
her get ready for a ball later that afternoon
Everyone is in awe of Marie’s beauty, and she shares a dance with Louis in front of everyone
later, She finds him outside painting a picture of his late wife
and He tells Marie that she reminds him of her
Louis appoints Lintillac with the title of Duke and later holds a dinner in his honor
Yves and his crew discuss their tale of sailing to capture the Mermaid
to which Lintillac makes snide comments prompting
him to fire back with more comments that offend him
After dinner, Marie goes to visit the Mermaid again and goes underwater to be closer to her
later, Yves takes Marie to ride horses but she falls off and severely breaks her arm
Labarthe states that the arm will need to be amputated
to prevent infection even though everyone thinks there must be another way
later, Yves carries Marie along with Magali to see the Mermaid and places her in the water
and The Mermaid uses her powers to heal Marie’s arm completely
they are amazed at the Mermaid’s true power
After seeing how Marie’s arm has healed,
she assumes that Louis has brought the Mermaid to France to heal the citizens from sicknesses
but she is told that the Mermaid is for the King’s purpose only
and She walks around the courtyard with Yves
Louis arranges for Lintillac to marry Marie so that they can share in Lintillac’s fortune
La Chaise summons Marie after she spends more time with the Mermaid, who took her swimming
Louis comes clean to Marie about him being her father
and then tells her that he wants her to marry Lintillac
She refuses and runs away crying leaving Louis feeling remorseful
La Chaise goes to visit the Mermaid and she communicates with him telepathically
Realizing she is a living creature with feelings, he confronts Labarthe about
killing her to fulfill the King’s wishes, but Labarthe fully plans to go ahead regardless
La Chaise brings his complaints to Louis, who also refuses to change his mind
Meanwhile, Marie goes to see the Mermaid herself
and she shows her a vision of Yves being the one to capture her
Yves slips the picture of the procedure under Marie’s door
alerting her to the King’s real plans for the Mermaid
She trashes the musical instruments and then confronts Louis over his plans
She says that she will marry Lintillac if he lets the mermaid go
but he refuses to honor her wishes
As everyone prepares for the wedding,
La Chaise goes to Marie’s room to quietly bring her to save the Mermaid
The two go to the chamber, where Yves is also trying to get the Mermaid out
Although Marie reminds him of how he captured the Mermaid, he is committed to setting her free
They are found by Labarthe and another goon
but they fight them off to give the Mermaid time to escape
Labarthe shoots Yves who falls into the water
and The Mermaid pulls Yves with her as she swims out
Marie gets Labarthe caught in a rotating wheel that pulls him underwater
she makes it to the side of a cliff, where she sees Yves is okay
Louis and his men arrive, and prepare to shoot the Mermaid to go through with the procedure,
but Marie gives Louis the choice to save his own life or his daughter’s
She jumps off the cliff and hits the water hard enough to injure her severely
The Mermaid grabs Marie and Louis has no choice but to tell his men
to stand down with their rifles so that the Mermaid can revive Marie
She and Yves swim to his boat while Louis watches them leave
and finally the Mermaid swims home
La Chaise tells Louis, he is now a great king and a great man
Marie and Yves sail to find the city of Atlantis
so that Marie may reunite with the Mermaid and she takes her underwater
to see the city up close