Today is the end of the tenth cycle of the moon. At midnight, Arthur will finally return to the world of the Minimoys, located below the ground of his grandfather Archibald's farm. In the village of these tiny beings, a banquet is going to be held in honor of the valiant Arthur. But on the afternoon preceding the banquet, Archibald becomes angry at Arthur's father, who tries to kill bees because his son is allergic to their sting. Arthur's father decides to take his son home a day earlier than planned, despite his wife's objections. As they're leaving, a spider gives Arthur a grain of rice that has a distress message carved into it. Convinced that his beloved friend Selenia is in danger, the boy manages to be miniaturized and arrives in the village of the Minimoys, where everything is in order. As it turns out, Maltazar sent Arthur the message so he could use Arthur's passage back, leaving the boy stuck in the Minimoy kingdom.