Elena reconnects with her cousin Duke Cristóbal, who has been keeping watch over the city of Nueva Vista; while there, she befriends a group of mermaidlike sea creatures called sirenas and enlists their help to defeat evil sorceress Shuriki.

On Día de los Muertos, Elena and her abuelo team up with the spirits of two of his old friends, El Guerrero and El Místico, to complete a mission that they had started many years ago and were not able to complete.