On a fateful Halloween, a young chimney sweep named Lubicchi forges a bond with a man manifested from refuse, whom he names Poupelle. Together, they challenge the oppressive rule of the Inquisitors, seeking to unveil the town's obscured history and forbidden knowledge. Their unconventional friendship draws both admiration and scrutiny, facing threats from the Inquisitors and skeptical townsfolk. Despite the challenges, Poupelle's influence on Lubicchi is profound, leading them to uncover the truth and dispel the smokescreen veiling the town's skies.