Half unicorn, half mermaid Sirena is excited to start Mermicorn Magic School, but she soon realizes that magic is much harder than she imagined.

Mermicorns Serena and Lily try to use simple invisibility magic while doing a school project about magical mistakes, and learn a powerful lesson about using magic responsibly.

"Lucky the mermicorn has a special talent for finding just the right kind of magic to help his friends. So when Echo the dolphin needs extra dolphins to enter the Perfect Pearl Path Scavenger Hunt, Lucky swims to her rescue. By using a new, fin-credible shell that can multiply anything, Lucky creates extra Echos. But extra dolphins soon become more than even the Fin-tastic Four can handle! The dolphin copies are causing all kinds of chaos, all over...

"The best time of the year has arrived-- Mermicorn Island's annual costume contest. Lucky loves designing ever more elaborate costumes for his Fintastic Four, in the hopes of finally taking home the grand prize. But when a fierce-looking shark crashes the ball, everyone swims for cover." -- provided by publisher.