Electra, the nine-year old mermaid with legs instead of a tail is back and in search of even more adventure! It's New Year on Mermaid Island. Every year a young Queen of the New Year is elected and Electra is desperate to be chosen! So she might be picked, Electra and her dolphin friend, Splash, decide to help the grown-ups decorate the grotto for the New Year Party. But Electra and Splash get carried away and make a BIG mess in the grotto. Sent away to behave, they discover tunnels at the back of the grotto leading to the deep sea. All the tunnels are safely blocked up except one. Electra and Splash try and tell the adults but they are too busy fixing the mess to listen! So when a group of sharks swim down the tunnel and threaten to eat everybody it's up to Electra and Splash (and a giant ink squirting squid) to save the day!