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 Radames, captain of the Egyptian guard, secretly love each other, but Amneris also loves Radames. One day, Radames returns from a victorious campaign bringing with him many slaves, including Aida?fs father Amonasro. The Ethiopian king Amonasro sees his daughter again and convinces her to find out from Radames which route the Egyptian forces plan to take in the next war with Ethiopia. At night, Aida, in a rendezvous with Radames 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, Radames 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, Radames discovers that Aida has concealed herself in the darkness. The lovers die quietly but at the same time attain eternal love.