Ariel puts on a human bracelet but finds it hard to take it off afterwards. Afraid of how her father would react, Ariel runs away to find the key to the lock of the bracelet.
Ariel believes her father King Triton is setting her up for an arranged marriage with a snobbish merman-prince of another sea kingdom of Olympia named Prince Thor.
Ariel accidentally frees a dark figure known as the Evil Manta, who tries to take over Atlantica using deception and lies to turn its merfolk people against each other.
Before a family trip to the Carnival of Tides on the tide, Ariel and Arista get into a fight and are 'beached' and Sebastian had to stay and look after them.
Pearl, a mermaid who is obsessed with partying, takes Ariel and her sixth eldest sister, Alana, to Eel-Ectric City instead of to her house, while Sebastian and Flounder follow.
