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.
When mermaid Echo Reef learns her classmate has a pet seahorse, she becomes determined to get one as well. Before long, however, she may realize that keeping a sea horse as a pet is a more daunting prospect than she imagined.