 On the eve of the coronation of King Rudolf V of Ruritania, his younger half-brother Michael, Duke of Strelsau, has him drugged.The unconscious king is abducted and imprisoned in a castle in the small town of Zenda.There are complications, plots, and counterplots, among them the schemes of Michael's mistress, Antoinette de Mauban, and those of his dashing but villainous henchman, Count Rupert of Hentzau.