Life has been good for Greta Whiteshark in Mermaid Cove. She has three amazing friends in Pearl, Nina, and Isla, and each day delivers a new adventure for the fin-some foursome.
But Greta’s busy new life has left her oldest friend, Morgan, feeling left out. Fortunately, all that is about to change when Greta plans a special outing for just the two of them at the Famous Mermaids and their Pets museum exhibit, or at least thats what Morgan thinks. But Greta has also invited the Mermaids and their Pets for a big group hang. Morgan is seriously miffed. No, he's crushed. Fine, he's cruffed.
Meanwhile, a hidden threat is developing at the museum when someone accidentally releases the spirit of a magical Mermaid Siren and her Pet Jellyfish—a dead-ringer for Morgan, who will do anything to get away from his controlling master.
The old- and new-world problems collide at the museum when Morgan storms-off and the Siren mistakes him for her jellyfish and takes him captive. Worse yet, the Siren’s jellyfish escapes his former master, just in time for Greta to mistake him for her beloved friend.
And so, while Morgan finds himself trapped and forced to serve the twisted Siren, Greta pulls out all the stops to make-up for her blunder, but with the WRONG JELLYFISH. And jealousy gets the best of Morgan when he witnesses Greta giving special treatment to the imposter jellyfish. Feeling deeply hurt, Morgan decides to lean-in and help his NEW best friend, the Siren, as she plans her biggest, most vengeful Siren’s Song performance ever. Of course, Morgan doesn’t realize he is putting every pet in Mermaid Cove in danger by helping with her plan. Oops.
Will all the pets in Mermaid Cove fall under the dangerous spell of the powerful Siren, or will Morgan and Greta's special bond be mended in time to save their friendship, and all the other best friends of Mermaid Cove?
