Queen Iris is delighted when the all-knowing wondrous fig tree, which stands in the middle of Fairyland, gives her Lala on her coronation day. But Lala is no ordinary fairy child. He shows very little interest in the spells he learns in fairy school and prefers the company of humans, befriending a recently orphaned girl, Beata, and her uncle. The queen hopes her son’s behavior will improve after she marries Amalfi, the captain of the palace guard, who already loves the prince as his own.

Meanwhile the power-hungry Adderpater, wizard, scholar, and coregent of the land, identifies the cause of the prince’s strange behavior: Lala has a human heart. The punishment for having a human organ is cruel in Fairyland. Iris will do anything to save her son, even marry the ancient wizard and banish Gigi, the truth-telling unicorn. Will the lights of Fairyland go out forever? Or will Lala’s human heart give him the courage to restore justice and happiness?