Scarlet runs into one of her teachers from school, Professor Fychfud, who now runs the Aquarium. He takes Scarlet on a tour. When they get to the piranha tank, Scarlet sees human remains, and then finds herself pushed into the tank. She gets free and accuses the Professor, who denies wrong-doing. Scarlet and Sandy come back that night to investigate, but by then the Professor is in the grips of the real villain.; An advertising scheme to drum up business at the beach-side hot dog stand goes too far.