Charles IV, Czech king and Holy Roman Emperor, has built Karlstejn castle to house the crown jewels. More importantly, it is a place of relaxation and meditation, so no women are permitted, and no politics are to be discussed. His young wife misses him, and hearing of the prohibition, resolves to sneak in for a night. At the same time, a country girl needs to prove she has spent one night at Karlstejn to get her potential fiance's father to agree to let her marry him. Both women dress up as pages. Things get complicated when a foreign dignitary comes to discuss politics, the queen is the page guarding Charles' bedroom, and the country girl is keeping watch on the walls of the castle.