Don Salluste, the former Chief of Police in Spain, is seeking revenge against the Queen after being exiled from the court. He meets Ruy Blas, a young student who bears a striking resemblance to his nephew, Don Cesar. Salluste manipulates the situation by disguising Ruy as Don Cesar and introducing him to the court. Ruy's intelligence, kindness, and generosity make him an instant hit with the people, including the Queen, who falls in love with him and even appoints him Prime Minister. But despite Ruy's success, Salluste's vengeful plan is still in motion.