A shark has been spotted in Trident City! Pearl Swamp is so scared, she needs a shark Guard to escort her to and from school. She doesn't trust anyone who likes these terrifying creatures, especially Kiki Coral, who isn't nearly as frightened as Pearl. And to make matters worse, Pearl accuses Kiki of stealing her precious pearl necklace! Will the sharks destroy the peace of their sparking city? Or will the mergirls have to swim in dangerous deep-sea waters?