Task: Question Generation
Input (English):  A King and a Queen, who have several children, decide to journey across their Kingdom. One day, the stop in a castle at the frontier and the Queen gives birth to a beautiful princess. Because of this, the courtiers name her Fairer-than-a-Fairy. But no sooner has the Queen recovered that she must join the King, who has gone to defend a faraway province attacked by their enemies.
When Fairer-than-a-Fairy is twelve, her beauty becomes famous in all the surrounding countries. The Fairies become jealous of her beauty and her name and decide to avenge themselves and destroy the Princess  beauty. The Queen of the Fairies, named Nabote, goes to the castle in order to kidnap Fairer-than-a-Fairy but she finds it impossible, because the wizard who built it put a spell so that its inhabitants could neither go out unwillingly, nor be bewitched.
Nabote goes into the castle as a servant and makes friends with Fairer-than-a-Fairy. One day, she opens a door that gives onto the countryside and pretends to faint outside the castle s walls. Fairer-than-a-Fairy runs to her but no sooner has she gone out that Nabote seizes her and takes her to her Kingdom. There she dresses Fairer-than-a-Fairy with dirty clothes and instructs her to clean a room which will only become dirtier as she sweeps it.
Nabote s son, Phratis, professes his love for her and magically cleans the room. He gives Fairer-than-a-Fairy a key and tells her to open the main panel in her cell. She obeys and meets D sirs, another princess who was kidnapped because she was beautiful without the assistance of the Fairies  gifts.
When the Fairies find that the two princesses have fulfilled the tasks, they order Fairer-than-a-Fairy to go on Mount Adventurous and fill a vase with the Water of Immortal Life. They give her feathers and wax, hoping she will crash like Icarus. D sirs is sent on the beach and ordered to write something on the sand on condition that it will not fade. Phratis helps Fairer-than-a-Fairy and she asks him to complete D sirs  task.
Finally, Fairer-than-a-Fairy is instructed to capture the Hind with Silver Feet and D sirs is sent to the Fair of Time in order to fetch the Rouge of Youth.
At the fair, D sirs meets a wicked Fairy who keeps her in a prison and sends for an evil spirit in order to make her ugly. D sirs is rescued by her lover who has been instructed by a sage to bring her back to the Queen of the Fairies.
Meanwhile, with the help of Phratis, Fairer-than-a-Fairy finds the Hind, who is revealed to be the former Queen of the Fairies under an enchantment. The Queen and Fairer-than-a-Fairy return to Nabote s court, where they save D sirs from being executed, and D sirs  lover is revealed to be Fairer-than-a-Fairy s brother.
The former Queen retakes her throne, sends Nabote to another kingdom, and arranges the marriages of the two couples.
Output (English): What makes it impossible for Nabote to kidnap Fairer-than-a-Fairy?