Answer
In "The Prisoner of Zenda", Stewart Granger portrayed Rupert of Hentzau, the malevolent brother of the king. The narrative revolves around the king's doppelganger, who assumes the throne after the king's abduction. Complications ensue as the doppelganger grapples with the responsibilities of ruling and falls in love with the princess, while Rupert plots to seize power. The film blends adventure, romance, and political intrigue, showcasing Granger's versatility as an actor.