[1] The film is based on Anthony Hope's classic 1894 English novel, The Prisoner of Zenda, and was adapted by Leonard Lee.

He recalls that his father had mentioned that he, Michael, should be king, if and when his brother died; thus, he begins to devise a plan to cause Rudolph's death.

When she confronts him, Michael sends Antoinette away and tells her that if he can't count on her loyalty, she is no longer his wife.

Pretending that his intentions were to congratulate Rudolph stepping up to the throne, Michael drugs his brother causing him to enter a deep coma, only a few days prior to his coronation.

When they defeat Michael, the young prince Rudolph becomes the king of Ruritania and takes his father's place at last.