The night after Cheval’s birthday, an enormous earthquake shakes the land. Cheval’s house is destroyed. Everyone pitches in, and the rebuilding is progressing well. Strangely, when he awakes in the morning, the rebuilt walls of Cheval’s house have disappeared. Our heroes are perplexed. How do walls evaporate into thin air? Cheval gets back to work, but the next day, the walls have once again disappeared! They want an explanation, so they stand guard, leading to the discovery of an unknown world with its curious inhabitants.