Princess Cali and her twin brother, Prince Cruise, are expected to do everything together -- but at the Royal Mermaid Rescue Crew School, Cali wants to stand out on her own. So when the principal announces a Rescue Crew Tournament to name the top merstudent of the year, Cali is thrilled. This is the perfect way to prove herself! But Cruise is a tough competitor. Will Cali do anything to win...even something fishy?