Unipiggle and Princess Pea are so excited to be on HOLIDAY! They can't wait to build sandcastles and explore the magical underwater town, Mermaid Springs. But then the King is swept away in a WHIRLPOOL. The mermaids think he has been taken by a mysterious undersea creature - who likes to BURP a lot. Can Unipiggle and Princess Pea brave the bubbles to find his secret lair and save the King?