Little Elliot gets his big sister Emma to enter the Grand Sand Sculpture contest with him. Meanwhile Cleo's day starts badly at the Oceanic Center: Mr. Lambert puts her in charge of the new intern - Miriam, the Mayor's daughter and high school pest! Miriam lives up to her reputation, and submits Cleo to a series of capricious outbursts. The injured turtle they are supposed to be monitoring escapes while the two teenagers are arguing, and swims out to sea. Our three mermaids mount a salvage operation that proves very risky...
