H2O: Just Add Water | Season 5

Far Longer Than Forever, Pt. 2 (Prologue)

Once upon a time, many years ago, a powerful merman started a war against all mermaids. He designed the merman chamber, in order to destroy all mermaids across the world by combining a powerful trident and the full moon to absorb power from the moon pool and subsequently every mermaid's life.
The merman who built it then fell in love with a beautiful mermaid, and decided to activate it, and instead found ways to invoke peace and stop the war once and for all.
But some still had range in them - like the powerful mermaid Aurora, who made it her goal to eliminate all merman forever. For thousands of years she survived, slowly hunting down mermen around the globe, taking away their powers or sending them to land - forever.
But when as new threat is rising, she would stop at nothing before finishing what she started.