On Halloween, Lubicchi, a young chimney sweep, encounters a man who has been created miraculously out of trash. By giving him the name Poupelle, Lubicchi is able to rebuild the relationship that was broken when his father perished under the control of the Inquisitors—a repressive group that seeks to stifle outside knowledge and the town's true history. But when word of their newfound relationship spreads, the Inquisitors' threat and even some town residents' criticism will put their friendship to the test. Despite this, Poupelle has a special connection with Lubicchi, and the two work together to expose the truth and remove the chimney smoke that is obscuring the town's skies.