Unable to comprehend a beloved librarian's imminent marriage to a cafeteria worker who seems to be perpetually grouchy, Pearl becomes jealous when Echo, Shelly, and Kiki are all asked to be flower girls.

Echo's third grade class visit the Titanic and figure out a way of including their new classmate, Anita, who is confined to a wheeled chair.

When her class at Trident Academy visits a pod of whales, Kiki Coral must overcome her fears with the help of her friends.

When sharks are spotted in Trident City, Pearl is assigned a Shark Guard for safety and begins stirring up trouble by denouncing all shark-related activities before wrongly accusing a friend of stealing.

Echo Reef is tail-flipping with excitement when she find a human object. But when her older sister claims the object for her own, how far will Echo go to reclaim it?

Listening to her aunt's story about a fairy that visits mermaids while they sleep to purposely tangle their hair, Echo resolves to catch the fairy in the act before her skeptical friends ask her to figure out whether or not fairies are even real.

When Echo twists her tail while riding Rocky's seahorse, she is told she cannot perform as the star tail flipper on Trident Academy's team, and she must come up with a way to help her team win.

Longing for onstage stardom, Pearl auditions for the third-grade play and gets the part of the evil sea witch while her best friend is cast in the lead, a situation that challenges their friendship.

Longing for a sea horse of her own after learning that a classmate from Trident Academy has one, Echo Reef becomes involved in a local debate about whether or not domesticated sea horses can be happy.

Shelly is a princess! A real princess! It's been a well-kept secret in Trident City, but now the word is out, and Shelly doesn't know how to act! Should she start wearing a glittery crown? Or move to a grand undersea palace? Will her friends have to call her Your Highness? Being a princess may be exciting, but Shelly's not sure she can truly play this royal part.