Seven years since the Monsterpocalypse began, Joel Dawson has been living underground in order to survive. But after reconnecting over radio with his high school girlfriend Aimee, Joel decides to venture out to reunite with her, despite all the dangerous monsters that stand in his way.

When a dark secret from this past threatens to be exposed, unorthodox and brilliant medical examiner, Doctor Daniel Harrow, must use all his forensic skills to keep it buried forever.

H2O: Just Add Water revolves around three teenage girls facing everyday teen problems with an added twist: they cope with the burden of growing a giant fin and transforming into mermaids whenever they come in contact with water.