The Loud family sets off on a big adventure to Scotland, and as they discover their Scottish royal origins, their life quickly goes upscale when they discover that their ancestral home is a castle.
As Lincoln and his friend Clyde seek to spend the perfect Halloween night, the duo becomes torn between spending the day at Loud's house, going to their friend Xander's party, or embarking on road adventures.
As Lincoln and the Louds prepare to welcome Myrtle with a grand celebration, a former enemy of Myrtle appears on the island, prompting the group to embark on a major espionage mission.