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 Mermicorn Island. Lucky has to put a stop to it—before the real Echo takes all the blame!