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.

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.