Lincoln and the Louds are ecstatic to welcome their new Gran-Gran, Myrtle, into the family with a tropical wedding celebration; but the festivities are cut short when an old nemesis from Myrtle's secret agent past appears on the island.
Aspiring songwriter Ricky Barry (Kel Mitchell) finally gets the break he's been waiting for when he enters a song in a contest and wins. But instead of being a ticket to the top, his triumph lands him nothing more than a mail room job at a record company when his tune is recorded by singing superstar Kennedy Ross (Bombay). Determined to prove Kennedy's a phony, Ricky sets out to discredit her, but his plans fall apart when he falls in love.
Oscar is a small fish whose big aspirations often get him into trouble. Meanwhile, Lenny is a great white shark with a surprising secret that no sea creature would guess: He's a vegetarian. When a lie turns Oscar into an improbable hero and Lenny becomes an outcast, the two form an unlikely friendship.