Do you believe in mermaids?

When three normal girls stumble upon an ancient cavern they undergo a transformation that will change their lives forever. H2O Just Add Water sees three very different girls facing everyday teen problems with a twist -- they're mermaids with incredible powers!Rikki, Cleo and Lewis think they know everything there is to know about Mako Island, but when water attacks the girls in a full moon, they realise a new, potentially dangerous force is developing on the mysterious island. Thankfully they find an ally in Bella, a new girl in town who reveals an equally surprising twist; she too is a mermaid with extraordinary super powers.