The young queen Eliška Pomořanská (Elizabeth of Pomerania) waits in vain for her husband Emperor Karel IV. (Charles IV) to join a celebration at the Prague Castle. The king is busy with state duties. Eliška at least looks forward to taking a journey with Karel to Karlštejn castle. To her great surprise, she learns that women are banned from Karlštejn. She finally goes to the small castle of Karlík to be closer to her husband. – At Karlštejn, everything is being prepared for the Emperor's arrival. The guests, the Cypriot king Petr and the Bavarian archduke Štěpán, are already there. Neither of the royal guests believes that the ban on female visitors is going to be strictly observed but even they do not suspect that the orders have already been broken. Not just one but two women have already found their way into Karlštejn. One is the Queen Eliška, and the other Alena, the burgrave's niece dressed as a pageboy who has laid a wager with her father that she will spend a night at the castle.