After Sofia helps a little mermaid named Oona, Sofia's amulet grants her the power to transform into a mermaid and visit her new friend's secret underwater kingdom. But when Cedric plots to steal Oona's enchanted Mermaid Comb, danger surfaces for both worlds. With a little help from special guest, Princess Ariel, Sofia embarks on an adventure to rescue Oona and prevent a typhoon before it₂s too late.

The Mallard family is in a bit of a rut: while dad Mack is content to keep his family safe paddling around their New England pond forever, mom Pam is eager to shake things up and show their kids - teen son Dax and duckling daughter Gwen - the whole wide world. After a migrating duck family alights on their pond with thrilling tales of far-flung places, Pam persuades Mack to embark on a family trip, via New York City, to tropical Jamaica.