The setting is ancient Egypt. Aida, princess of Ethiopia who was defeated in the war, is a captive and slave to the Egyptian princess Amneris, who does not know that Aida is the daughter of the Ethiopian king. Aida and Radamès, captain of the Egyptian guard, secretly love each other, but Amneris also loves Radamès. One day, Radamès returns from a victorious campaign bringing with him many slaves, including Aida’s father Amonasro. The Ethiopian king Amonasro sees his daughter again and convinces her to find out from Radamès which route the Egyptian forces plan to take in the next war with Ethiopia. At night, Aida, in a rendezvous with Radamès on the bank of the Nile, tries to persuade him to flee with her and extracts from him information about the operations of the Egyptian forces. Stunned to know of the enemy’s plot, Radamès surrenders himself and is placed under arrest. Amneris offers to plead for him if he marries her, but ultimately, he refuses to explain and is sentenced to death. As the walls of his burial chamber are sealed up, Radamès discovers that Aida has concealed herself in the darkness. The lovers die quietly but at the same time attain eternal love.