A young boy named Joshua Waits is visited by the ghost of his grandfather, Seth, who warns him about the dangers of goblins despite being dismissed by Joshua's family as mere nightmares. The Waits family embarks on a vacation to the rural farming community of Nilbog, which Joshua's parents hope will bring them closer as a family. They agree to a house exchange with a peculiar family from Nilbog, eager to spend a month in the city. However, Joshua continues to receive ominous messages from Grandpa Seth, urging him to protect his family from impending doom.

Upon arriving in Nilbog, the family encounters a series of strange occurrences and eccentric townsfolk who are overly keen on having them eat the local food, which Joshua is warned against by his grandfather's spirit. Meanwhile, Joshua's sister, Holly, contends with her relationship with her boyfriend, Elliot, who has followed them to Nilbog along with his friends, ignorantly unaware of the bizarre situation developing. As the family's situation becomes increasingly peculiar, Joshua begins to uncover the dark secret underlying the town of Nilbog, realizing that the threat of goblins Grandpa Seth warned him about is not only very real but also intimately connected to the town's residents and their sinister intentions.