It's summer time, but not everything is fun in the sun for Bella, Cleo, Rikki, Will, Lewis, and now Emma! New and old threats arise forcing the mermaid crew to join hands and work together.
Emma feels left out coming back and seeing a new mermaid taking over HER turf.
Bella feels used seeing that Cleo and Rikki became friends with her right after Emma's departure.
Cleo and Rikki are conflicted, choosing either one mermaid or getting all four mermaids together.
Will feels conflicted, having to choose between two girls, both who are important to him.
Lewis has to choose between giving up or defending Cleo, risking himself and their relationship in the process.
Zane returns, thinking he can just come and sweep Rikki off her feet.
Sophie, also returns, hoping that the kiss seals the deal between Zane and her.
Secrets are revealed, some bigger than others. Some as big as the mermaid secret.
One threat comes back, with another trailing behind.
To see the whole picture, read H2O: Season 4!!!
(Sorry this description is so bad, it's my first Wattpad)