The Sea Keepers are off to Australia to help their mates, the Oceania mermaids! Divers are threatening their beautiful coral reef and evil siren Effluvia has bewitched a dangerous shark to spoil the mermaids' tropical talent show. Now all the fish who live there are in danger! Can Emily, Grace, and Layla find the magical pearl to save the show and protect the reef without becoming a shark's snack?