Prince Caprice is tormented by wanderlust. The prospect of taking over the affairs of state from his father, King Zack, does not sit well with him. Instead, he wonders: Is there no Plan(et) B? When the moon rises, Caprice suddenly knows where his longing is leading him... Without hesitation, he turns his illusion into reality and flies to the moon, accompanied by King Zack and the scholar Mikroskop.
It quickly becomes apparent: different planets, different customs. When Caprice falls in love with the Moon Princess Fantasia, they both experience the consequences, for on the moon, love is considered a disease!
It is one of humanity's great dreams: the journey to the moon. Jules Verne, for example, explored it in his early science fiction classics for young readers. In 19th-century France, the subject was very much in vogue. Composer Jacques Offenbach incorporated this imaginative world into his grand opera Die Reise zum Mond / Journey to the Moon, immediately achieving great success with the audience.