Little House on the Prairie: Season 3, Episode 5

3 - 5: The Monster of Walnut Grove

On Halloween night, Laura and Mary get permission from their parents to walk into town and pull a little prank at the Mercantile. Laura's imagination runs wild when she peeks into the Olesons' window and witnesses Nels committing an unspeakable crime. Scarred by what she has seen, Laura can't get anyone to believe her.