A class trip to a beautiful island is overshadowed by a local myth about a mysterious ship that may have ties to the lost city of Atlantis.

Four children set out to capture a mermaid, but she manages to escape all of their traps.

When she incurs Neptune's wrath by finding a diamond ring buried under rocks in the ocean, Emily is put under a curse that will force her to choose to be either a mermaid or a human and split up her parents forever.

When young Pearl, a mermaid, becomes caretaker of a single grain of sand, she discovers that performing even the smallest task well can transform the world.

Emily Windsnap enjoys a peaceful existence with her fellow merpeople friends on Allpoints Island, but when she learns that they need to return to Brightport, where construction projects threaten a secret mermaid community, Neptune asks the Windsnap family to solve the problem.

After recieving a message from Skystar, the princess of the seaponies, Fluttershy and her best friends head to Seaquestria for an underwater vacation.

When the other WellieWishers see how much Camille misses living by the sea, they plot to turn their garden into an ocean.

When Shelly and the rest of her class discover that she is a princess, she is not sure how to act.

"Tallulah the mermaid realizes that she is different from the other mermaids in the ocean and finds that she truly belongs in the Great Lakes"--Provided by publisher.

"Can superheroes Bubbleboy and Guppygirl save the day?"--Provided by publisher.