Fan Casting

Ariel and Eric celebrate the birth of their newborn daughter Melody on a ship at sea. Ariel's father King Triton presents Melody with a magic locket. The party is interrupted by Ursula's sister Morgana, who threatens to have Melody fed to her pet tiger shark, Undertow, unless Triton surrenders his trident to her. Morgana then announces her plan to use the trident to avenge Ursula and take over the ocean. Ariel and Eric work together to foil Morgana's plan, and Triton shrinks Undertow to the size of a piranha. Morgana escapes, eluding the attempts of King Triton's forces to capture her and declaring that she will someday exact her revenge on both Ariel and Triton and avenge Ursula's death. Fearing Morgana and remembering Ursula, Ariel decides that, until Morgana is captured, they will have to withhold all knowledge of the sea world and her heritage from Melody in order to protect her. Triton tosses the locket into the ocean, and a massive wall is built to separate the royal castle from the sea. Triton assigns Sebastian to watch over Melody like he did with Ariel in the first film. 12 years later, Melody remains unaware of her mother's mermaid heritage and is forbidden from ever going into the sea. However, she has been sneaking out of the castle regularly to swim, and one day finds the locket. Seeing her name on the locket, Melody questions her mother about it, but Ariel furiously confronts Melody and forbids her to go into the sea. Frustrated with her mother's refusal to answer her questions, Melody steals a small boat and sails away from home. Melody is discovered by Undertow, who leads her straight to Morgana. In a panic, Sebastian confesses to Ariel and Eric that Melody went out to the sea. Meanwhile, Melody meets Morgana, who reveals that Melody's background is marine, and uses the remains of Ursula's magic to transform Melody into a mermaid. Triton prepares search parties, and is convinced by Ariel and Eric to use his trident to transform Ariel back into a mermaid in order to help in the search for Melody. Ariel searches the sea for Melody, regretting not sharing her heritage with her, while Melody explores her newfound abilities as a mermaid, and has a strong feeling that she was meant to be part of the sea. Melody visits Morgana to thank her, only for Morgana to tell Melody that the spell was only temporary, and that she can only make the spell permanent if Melody retrieves the trident from Triton, which Morgana claims he stole from her. Melody decides to get the trident, and during her search befriends Tip and Dash, a penguin and walrus duo who join her. Melody succeeds in stealing the trident, and returns to Morgana, but before Melody can hand the trident over to Morgana, Ariel arrives and pleads for Melody not to give Morgana the trident. Melody refuses to listen to Ariel, having been angered by Ariel's decision to lie to her, and gives Morgana the trident. With the trident in her power, Morgana reveals her true intentions and grabs Ariel with her tentacles, taking her hostage. Morgana then reveals to Melody that she stole from her grandfather and throws her against the wall, trapping her in a cave by sealing the entrance with a thick layer of ice and informing her that her time as a mermaid is about to expire. Soon afterward, Morgana's spell on Melody wears off, causing her to revert into a human and nearly drown. Tip and Dash manage to free her and drag her to the shore. Morgana uses the trident's magic to lord over the ocean, rising to the surface to gloat. Scuttle, Triton, Sebastian, and Eric arrive, and a battle ensues against Morgana and her minions. Melody manages to grab the trident and throws it back to Triton, who encases Morgana in a block of ice, which sinks underwater. Melody reunites with her family, and Triton offers his granddaughter the choice of becoming a mermaid permanently. Instead, Melody uses the trident to disintegrate the wall separating her home from the sea, reuniting the humans and the merpeople.